Polynucleotides encoding IL-31 monoclonal antibodies

ABSTRACT

The present invention relates to methods of treating pruritic diseases, including but not limited to Contact dermatitis, Atopic Dermatitis, Drug induced delayed type cutaneous allergic reactions, Toxic epidermal necrolysis, Cutaneous T cell Lymphoma, Bullous pemphigoid, Alopecia wereata, Vitiligo, Acne Rosacea, Prurigo nodularis, Scleroderma, Herpes simplex virus, or combination thereof by administering IL-31 monoclonal antibodies. The invention further provides the hybridomas that generate the monoclonal antibodies.

This application is a divisional of U.S. patent application Ser. No.13/185,130, filed Jul. 18, 2011, now U.S. Pat. No. 8,568,723, which is adivisional of U.S. patent application Ser. No. 12/420,747, filed Apr. 8,2009, now U.S. Pat. No. 8,017,122, which is divisional of U.S.application Ser. No. 11/430,066, filed May 8, 2006, now U.S. Pat. No.7,531,637, which claims the benefit of U.S. Provisional Application Ser.No. 60/678,918, filed May 6, 2005, U.S. Provisional Application Ser. No.60/696,251, filed Jul. 1, 2005, and U.S. Provisional Application Ser.No. 60/711,600, filed Aug. 26, 2005, all of which are hereinincorporated by reference.

BACKGROUND OF THE INVENTION

The immune system hosts a wide range of specific cell types includinglymphocytes. Lymphocytes determine the specificity of immune reaction ina host and include two classes, the B lymphocytes, which are precursorsof antibody producing cells and the T lymphocytes, which are requiredfor certain regulatory functions such as the development of specificimmune responses.

Mature T cells may be activated, i.e., by an antigen or other stimulus,to produce, for example, cytokines, biochemical signaling molecules, orreceptors that further influence the fate of the T cell population.

B cells can be activated via receptors on their cell surface including Bcell receptor and other accessory molecules to perform accessory cellfunctions, such as production of cytokines.

Monocytes/macrophages and T-cells can be activated by receptors on theircell surface and play a central role in the immune response bypresenting antigen to lymphocytes and also act as accessory cells tolymphocytes by secreting numerous cytokines.

Natural killer (NK) cells have a common progenitor cell with T cells andB cells, and play a role in immune surveillance. NK cells, whichcomprise up to 15% of blood lymphocytes, do not express antigenreceptors, and therefore do not use MHC recognition as requirement forbinding to a target cell. NK cells are involved in the recognition andkilling of certain tumor cells and virally infected cells. In vivo, NKcells are believed to require activation, however, in vitro, NK cellshave been shown to kill some types of tumor cells without activation.

The interleukins are a family of cytokines that mediate immunologicalresponses, including inflammation. The interleukins mediate a variety ofinflammatory pathologies. Central to an immune response are T cells,which produce many cytokines and adaptive immunity to antigens.Cytokines produced by T cells have been classified as type 1 and type 2(Kelso, A. Immun. Cell Biol. 76:300-317, 1998). Type 1 cytokines includeIL-2, IFN-γ, LT-α, and are involved in inflammatory responses, viralimmunity, intracellular parasite immunity and allograft rejection. Type2 cytokines include IL-4, IL-5, IL-6, IL-10 and IL-13, and are involvedin humoral responses, helminth immunity and allergic response. Sharedcytokines between Type 1 and 2 include IL-3, GM-CSF and TNF-α. There issome evidence to suggest that Type 1 and Type 2 producing T cellpopulations preferentially migrate into different types of inflamedtissue.

The skin plays an important role in the immune system and consists oflayers. The epidermis is a surface layer. Underneath the epidermis isthe dermis, a layer of connective tissue. Underneath the dermis, is thehypodermis, a layer of large amounts of adipose tissue. Circulating Tlymphocytes migrate to the skin under normal and inflammatoryconditions. The cutaneous lymphocyte antigen (CLA) is considered ahoming receptor for T cells with tropism for the skin. Santamaria-Babi,L., Eur. J. Dermatol. 14:13-18, 2004.

Several diseases of the skin are known to express high levels of CLA+ Tcells, including atopic dermatitis, contact dermatitis, drug-inducedallergic reactions, skin-tropic viruses and viral associated pruritis,vitiligo, cutaneous T cell lymphoma, alopecia aerata, acne rosacea, acnevulgaris, prurigo nodularis, and bullous pemphigoid. There is a need totreat such skin T cell mediated diseases.

The demonstrated in vivo activities of the cytokine family illustratethe enormous clinical potential of, and need for, other cytokines,cytokine agonists, and cytokine antagonists. IL-31, a newly identifiedcytokine. IL-31, when over-expressed in mice, results in dermatitis-likesymptoms. Both skin-homing T cells and epidermal kerationcytes have beenimplicated in the pathology of skin diseases in humans. The presentinvention addresses these needs by providing antagonists topro-inflammatory cytokine IL-31. Such antagonists of the presentinvention, which may block, inhibit, reduce, antagonize or neutralizethe activity of IL-31, include soluble IL-31RA receptors andneutralizing anti-IL-31 antibodies. The invention further provides usestherefor in inflammatory disease, as well as related compositions andmethods.

DETAILED DESCRIPTION OF THE INVENTION

Prior to setting forth the invention in detail, it may be helpful to theunderstanding thereof to define the following terms:

As used herein, the term “antibodies” includes polyclonal antibodies,affinity-purified polyclonal antibodies, monoclonal antibodies, andantigen-binding fragments, such as F(ab′)₂ and Fab proteolyticfragments. Genetically engineered intact antibodies or fragments, suchas chimeric antibodies, Fv fragments, single chain antibodies and thelike, as well as synthetic antigen-binding peptides and polypeptides,are also included. Non-human antibodies may be humanized by graftingnon-human CDRs onto human framework and constant regions, or byincorporating the entire non-human variable domains (optionally“cloaking” them with a human-like surface by replacement of exposedresidues, wherein the result is a “veneered” antibody). In someinstances, humanized antibodies may retain non-human residues within thehuman variable region framework domains to enhance proper bindingcharacteristics. Through humanizing antibodies, biological half-life maybe increased, and the potential for adverse immune reactions uponadministration to humans is reduced.

The term “chimeric antibody” or “chimeric antibodies” refers toantibodies whose light and heavy chain genes have been constructed,typically by genetic engineering, from immunoglobulin variable andconstant region genes belonging to different species. For example, thevariable segments of the genes from a mouse monoclonal antibody may bejoined to human constant segments, such as gamma 1 and gamma 3. Atypical therapeutic chimeric antibody is thus a hybrid protein composedof the variable or antigen-binding domain from a mouse antibody and theconstant domain from a human antibody, although other mammalian speciesmay be used.

As used herein, the term “immunoglobulin” refers to a protein consistingof one or more polypeptides substantially encoded by immunoglobulingenes. One form of immunoglobulin constitutes the basic structural unitof an antibody. This form is a tetramer and consists of two identicalpairs of immunoglobulin chains, each pair having one light and one heavychain. In each pair, the light and heavy chain variable regions aretogether responsible for binding to an antigen, and the constant regionsare responsible for the antibody effector functions.

Full-length immunoglobulin “light chains” (about 25 Kd or 214 aminoacids) are encoded by a variable region gene at the NH2-terminus (about110 amino acids) and a kappa or lambda constant region gene at theCOOH-terminus. Full-length immunoglobulin “heavy chains” (about 50 Kd or446 amino acids), are similarly encoded by a variable region gene (about116 amino acids) and one of the other aforementioned constant regiongenes (about 330 amino acids). Heavy chains are classified as gamma, mu,alpha, delta, or epsilon, and define the antibody's isotype as IgG, IgM,IgA, IgD and IgE, respectively. Within light and heavy chains, thevariable and constant regions are joined by a “J” region of about 12 ormore amino acids, with the heavy chain also including a “D” region ofabout 10 more amino acids. (See generally, Fundamental Immunology (Paul,W., ed., 2nd ed. Raven Press, N.Y., 1989), Ch. 7 (incorporated byreference in its entirety for all purposes).

An immunoglobulin light or heavy chain variable region consists of a“framework” region interrupted by three hypervariable regions. Thus, theterm “hypervariable region” refers to the amino acid residues of anantibody which are responsible for antigen binding. The hypervariableregion comprises amino acid residues from a “Complementarity DeterminingRegion” or “CDR” (i.e., residues 24-34 (L1), 50-56 (L2) and 89-97 (L3)in the light chain variable domain and 31-35 (H1), 50-65 (H2) and 95-102(H3) in the heavy chain variable domain (Kabat et al., Sequences ofProteins of Immunological Interest, 5th Ed. Public Health Service,National Institutes of Health, Bethesda, Md. (1991)) and/or thoseresidues from a “hypervariable loop” (i.e., residues 26-32 (L1), 50-52(L2) and 91-96 (L3) in the light chain variable domain and 26-32 (H1),53-55 (H2) and 96-101 (H3) in the heavy chain variable domain; Chothiaand Lesk, 1987, J. Mol. Biol. 196: 901-917) (both of which areincorporated herein by reference). “Framework Region” or “FR” residuesare those variable domain residues other than the hypervariable regionresidues as herein defined. The sequences of the framework regions ofdifferent light or heavy chains are relatively conserved within aspecies. Thus, a “human framework region” is a framework region that issubstantially identical (about 85% or more, usually 90-95% or more) tothe framework region of a naturally occurring human immunoglobulin. Theframework region of an antibody, that is the combined framework regionsof the constituent light and heavy chains, serves to position and alignthe CDR's. The CDR's are primarily responsible for binding to an epitopeof an antigen.

Accordingly, the term “humanized” immunoglobulin refers to animmunoglobulin comprising a human framework region and one or more CDR'sfrom a non-human (usually a mouse or rat) immunoglobulin. The non-humanimmunoglobulin providing the CDR's is called the “donor” and the humanimmunoglobulin providing the framework is called the “acceptor”.Constant regions need not be present, but if they are, they must besubstantially identical to human immunoglobulin constant regions, i.e.,at least about 85-90%, preferably about 95% or more identical. Hence,all parts of a humanized immunoglobulin, except possibly the CDR's, aresubstantially identical to corresponding parts of natural humanimmunoglobulin sequences. A “humanized antibody” is an antibodycomprising a humanized light chain and a humanized heavy chainimmunoglobulin. For example, a humanized antibody would not encompass atypical chimeric antibody as defined above, e.g., because the entirevariable region of a chimeric antibody is non-human.

The term “genetically altered antibodies” means antibodies wherein theamino acid sequence has been varied from that of a native antibody.Because of the relevance of recombinant DNA techniques in the generationof antibodies, one need not be confined to the sequences of amino acidsfound in natural antibodies; antibodies can be redesigned to obtaindesired characteristics. The possible variations are many and range fromthe changing of just one or a few amino acids to the complete redesignof, for example, the variable or constant region. Changes in theconstant region will, in general, be made in order to improve or altercharacteristics, such as complement fixation, interaction with membranesand other effector functions. Changes in the variable region will bemade in order to improve the antigen binding characteristics.

In addition to antibodies, immunoglobulins may exist in a variety ofother forms including, for example, single-chain or Fv, Fab, and(Fab′)₂, as well as diabodies, linear antibodies, multivalent ormultispecific hybrid antibodies (as described above and in detail in:Lanzavecchia et al., Eur. J. Immunol. 17, 105 (1987)) and in singlechains (e.g., Huston et al., Proc. Natl. Acad. Sci. U.S.A., 85,5879-5883 (1988) and Bird et al., Science, 242, 423-426 (1988), whichare incorporated herein by reference). (See, generally, Hood et al.,“Immunology”, Benjamin, N.Y., 2nd ed. (1984), and Hunkapiller and Hood,Nature, 323, 15-16 (1986), which are incorporated herein by reference).

As used herein, the terms “single-chain Fv,” “single-chain antibodies,”“Fv” or “scFv” refer to antibody fragments that comprises the variableregions from both the heavy and light chains, but lacks the constantregions, but within a single polypeptide chain. Generally, asingle-chain antibody further comprises a polypeptide linker between theVH and VL domains which enables it to form the desired structure whichwould allow for antigen binding. Single chain antibodies are discussedin detail by Pluckthun in The Pharmacology of Monoclonal Antibodies,vol. 113, Rosenburg and Moore eds. Springer-Verlag, New York, pp.269-315 (1994); see also International Patent Application PublicationNo. WO 88/01649 and U.S. Pat. Nos. 4,946,778 and 5,260,203, thedisclosures of which are incorporated by reference for any purpose. Inspecific embodiments, single-chain antibodies can also be bi-specificand/or humanized.

A “Fab fragment” is comprised of one light chain and the C.sub.H1 andvariable regions of one heavy chain. The heavy chain of a Fab moleculecannot form a disulfide bond with another heavy chain molecule.

A “Fab′ fragment” contains one light chain and one heavy chain thatcontains more of the constant region, between the C_(H1) and C_(H2)domains, such that an interchain disulfide bond can be formed betweentwo heavy chains to form a F(ab′)₂ molecule.

A “F(ab′)₂ fragment” contains two light chains and two heavy chainscontaining a portion of the constant region between the C_(H1) andC_(H2) domains, such that an interchain disulfide bond is formed betweentwo heavy chains.

Molecular weights and lengths of polymers determined by impreciseanalytical methods (e.g., gel electrophoresis) will be understood to beapproximate values. When such a value is expressed as “about” X or“approximately” X, the stated value of X will be understood to beaccurate to ±10%.

All references cited herein are incorporated by reference in theirentirety.

The present invention is based in part upon the discovery of the use ofantibodies as antagonists to IL-31 thereby inhibiting inflammation ingeneral, and the symptoms of dermatitis and pruritic diseases. Theinvention provides the use of monoclonal antibodies to inhibit, reduce,prevent or minimize the effects of dermatitis and pruritic diseases asfurther described herein. In an embodiment, the dermatitis is atopicdermatitis. In another embodiment the dermatitis is prurigo nodularis.In another embodiment, the dermatitis is eczema. IL-31 is a newlydiscovered T cell cytokine which, when over-expressed in mice, resultsin dermatitis-like symptoms. See also, Dillon, et al., Nature Immunol.5:752-760, 2004. Both skin-homing T cells and epidermal kerationcyteshave been implicated in the pathology of skin diseases in humans. IL-31mRNA and protein expression is restricted to the skin-homing CLA+ T cellpopulation in both atopic dermatitis (AD) patients and normalindividuals, while analysis of the receptor for IL-31, IL-31RA, byimmunohistochemistry (IHC) suggests slightly higher levels of IL-31RAexpression on skin keratinocytes in skin biopsies from acute and chronicAD sufferers compared to normal individuals.

IL-31 is the HUGO name for a cytokine that has been previously describedas Zcytor17lig in a published U.S. patent application (See publicationnumber 20030224487, Sprecher, Cindy et al., 2003, incorporated herein byreference). See also, Dillon, et al., Nature Immunol., supra. Theheterodimeric receptor for IL-31 was also described in 20030224487 aszcytor17 (HUGO name, IL-31RA) which forms a heterodimer with OncostatinMreceptor beta (OSMRbeta). IL-31 was isolated from a cDNA librarygenerated from activated human peripheral blood cells (hPBCs), whichwere selected for CD3. CD3 is a cell surface marker unique to cells oflymphoid origin, particularly T cells. The polynucleotide andpolypeptide sequences for human IL-31 are shown in SEQ ID NOs: 1 and 2,respectively. The polynucleotide and polypeptide sequences for murineIL-31 are shown in SEQ ID NOs:3 and 4, respectively. As used herein theterm, IL-31 means IL-31 as used in U.S. patent publication number20030224487, as shown above. The secretory signal sequence of IL-31 iscomprised of amino acid residues 1 (Met) to 23 (Ala), and the maturepolypeptide is comprised of amino acid residues 24 (Ser) to 164 (Thr)(as shown in SEQ ID NO:2). Further N-terminal sequencing analysis ofpurified IL-31 from 293T cells showed an N-terminus at residue 27 (Leu)as shown in SEQ ID NO:2, with the mature polypeptide comprised of aminoacid residues 27 (Leu) to 164 (Thr) (as shown in SEQ ID NO:2).

The polypeptide sequence for the IL-31RA (IL-31 receptor) is shown inSEQ ID NO:5, and the polypeptide sequence for OncostatinM receptor beta(OSMRbeta) is shown in SEQ ID NO:6.

The IL-31RA and OSMRbeta receptors belong to the Class I cytokinereceptor subfamily that includes, but is not limited to, the receptorsfor IL-2, IL-4, IL-7, Lif, IL-12, IL-15, EPO, TPO, GM-CSF and G-CSF (fora review see, Cosman, “The Hematopoietin Receptor Superfamily” inCytokine 5(2): 95-106, 1993). The IL-31RA subunit is fully described incommonly-owned PCT Patent Application No. US01/20484 (WIPO publicationNo. WO 02/00721). Analysis of the tissue distribution of the mRNA of theIL-31RA subunit revealed expression in activated CD4+ and CD8+ T-cellsubsets, CD14+ monocytes, and weaker expression in CD19+ B-cells.Moreover, the mRNA was present in both resting or activated monocyticcell lines THP-1 (ATCC No. TIB-202), U937 (ATCC No. CRL-1593.2) and HL60(ATCC No. CCL-240).

Inhibition, neutralization, blocking signal transduction by the IL-31antagonists described herein can be measured by a number of assays knownto one skilled in the art. For example, assays measuring a reduction inproliferation include assays for reduction of a dye such as AlamarBlue™(AccuMed International, Inc. Westlake, Ohio),3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (Mosman,J. Immunol. Meth. 65: 55-63, 1983); 3,(4,5 dimethylthiazol-2-yl)-5-3-carboxymethoxyphenyl-2H-tetrazolium;2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazoliumhydroxide; and cyanoditolyl-tetrazolium chloride (which are commerciallyavailable from Polysciences, Inc., Warrington, Pa.); mitogenesis assays,such as measurement of incorporation of ³H-thymidine; dye exclusionassays using, for example, naphthalene black or trypan blue; dye uptakeusing diacetyl fluorescein; and chromium release. See, in general,Freshney, Culture of Animal Cells: A Manual of Basic Technique, 3rd ed.,Wiley-Liss, 1994, which is incorporated herein by reference. In additionto the above, see published U.S. patent publication number 20030224487,(Sprecher, Cindy et al., 2003) for an example of BaF3 cells expressingIL-31RA and full-length OSMRbeta.

In general, cytokines are predicted to have a four-alpha helixstructure, with helices A, C and D being most important inligand-receptor interactions, and are more highly conserved amongmembers of the family. Referring to the human IL-31 amino acid sequenceshown in SEQ ID NO:2, alignment of human IL-31, human IL-3, and humancytokine amino acid sequences it is predicted that IL-31 helix A isdefined by amino acid residues 38-52; helix B by amino acid residues83-98; helix C by amino acid residues 104-117; and helix D by amino acidresidues 137-152; as shown in SEQ ID NO:2. Structural analysis suggeststhat the A/B loop is long, the B/C loop is short and the C/D loop islong. This loop structure results in an up-up-down-down helicalorganization. Based on 4-helix bundle structure, the cysteine residueswithin IL-31 that are conserved correspond to amino acid residues 72,133, and 147 of SEQ ID NO:2; and 74, 137, and 151 of SEQ ID NO:4described herein. Consistent cysteine placement is further confirmationof the four-helical-bundle structure. Also highly conserved in the IL-31is the Glu residue as shown in SEQ ID NO:2 at residue 43. These helicesof IL-31 may be specific targets for inhibition, reduction orneutralization by the antibodies described herein for blocking theeffects of IL-31 signaling through its cognate receptor.

Based on comparison between sequences of human and murine IL-31conserved residues were found in the regions predicted to encode alphahelices C and D. The corresponding polynucleotides encoding the humanIL-31 polypeptide regions, domains, motifs, residues and sequencesdescribed herein are as shown in SEQ ID NO:1. These helices of IL-31 maybe specific targets for inhibition, reduction or neutralization by theantibodies described herein for blocking the effects of IL-31 signalingthrough its cognate receptor.

While helix D is relatively conserved between human and murine IL-31,helix C is the most conserved. While both species have predominantacidic amino acids in this region, the differences may account forspecies specificity in interaction between IL-31 and its receptor,IL-31RA comprising monomeric, heterodimeric or multimeric receptors.Loop A/B and helix B of IL-31 are marginally conserved, and helix Cthrough Loop C/D into helix D is most conserved between species;conservation through this region suggests that it is functionallysignificant. The D helices of human and murine IL-31 are also conserved.IL-31RA receptor antagonists may be designed through mutations withinIL-31 helix D. These may include truncation of the protein from residueThr156 (SEQ ID NO:2), or conservation of residues that confer binding ofthe ligand to the receptor, but diminish signaling activity.

Methods for preparing the polynucleotides encoding the antibodiesdescribed herein (including DNA and RNA) are well known in the art.Total RNA can be prepared using guanidinium isothiocyanate extractionfollowed by isolation by centrifugation in a CsCl gradient (Chirgwin etal., Biochemistry 18:52-94, 1979). Poly(A)⁺ RNA is prepared from totalRNA using the method of Aviv and Leder (Proc. Natl. Acad. Sci. USA69:1408-12, 1972). Complementary DNA (cDNA) is prepared from poly(A)⁺RNA using known methods. In the alternative, genomic DNA can beisolated. Polynucleotides encoding IL-31 antibodies are then identifiedand isolated by, for example, hybridization or PCR.

The polynucleotide sequence for the mouse ortholog of IL-31 has beenidentified and is shown in SEQ ID NO:3 Mature sequence for the mouseIL-31 putatively begins at Met₁, as shown in SEQ ID NO:4, whichcorresponds to Met₁, as shown in SEQ ID NO:2, in the human sequence.Tissue analysis revealed that expression of mouse IL-31 is found intestis, brain, CD90+ cells, prostate cells, salivary gland and skin.Further N-terminal sequencing analysis of purified IL-31 from 293T cellsshowed an N-terminus at residue 31 (Ala) as shown in SEQ ID NO:4, withthe mature polypeptide comprised of amino acid residues 31 (Ala) to 163(Cys) (as shown in SEQ ID NO: 4).

A Hopp/Woods hydrophilicity profile of the IL-31 protein sequence asshown in SEQ ID NO:2 can be generated (Hopp et al., Proc. Natl. Acad.Sci. 78:3824-3828, 1981; Hopp, J. Immun. Meth. 88:1-18, 1986 andTriquier et al., Protein Engineering 11:153-169, 1998). The profile isbased on a sliding six-residue window. Buried G, S, and T residues andexposed H, Y, and W residues were ignored. For example, in human IL-31,hydrophilic regions include amino acid residues 54-59 of SEQ ID NO:2,amino acid residues 129-134 of SEQ ID NO:2, amino acid residues 53-58 ofSEQ ID NO:2, amino acid residues 35-40 of SEQ ID NO:2, and amino acidresidues 33-38 of SEQ ID NO:2. For example, in mouse IL-31, hydrophilicregions include amino acid residues 34-39 of SEQ ID NO:4, amino acidresidues 46-51 of SEQ ID NO:4, amino acid residues 131-136 of SEQ IDNO:4, amino acid residues 158-163 of SEQ ID NO:4, and amino acidresidues 157-162 of SEQ ID NO:4.

Those skilled in the art will recognize that hydrophilicity orhydrophobicity will be taken into account when designing modificationsin the amino acid sequence of a IL-31 polypeptide, so as not to disruptthe overall structural and biological profile. Of particular interestfor replacement are hydrophobic residues selected from the groupconsisting of Val, Leu and Ile or the group consisting of Met, Gly, Ser,Ala, Tyr and Trp. For example, residues tolerant of substitution couldinclude Val, Leu and Ile or the group consisting of Met, Gly, Ser, Ala,Tyr and Trp residues as shown in SEQ ID NO:2. Conserved cysteineresidues at positions within SEQ ID NO:2 and SEQ ID NO:4, will berelatively intolerant of substitution.

The present invention also includes antibodies that bind functionalfragments of IL-31 polypeptides and nucleic acid molecules encoding suchfunctional fragments. A “functional” IL-31 or fragment thereof asdefined herein is characterized by its proliferative or differentiatingactivity, by its ability to induce or inhibit specialized cellfunctions, or by its ability to bind specifically to an anti-IL-31antibody or IL-31RA or antibody or IL-31RA/OSMRbeta heterodimers ofthese receptors (either soluble or immobilized). As previously describedherein, IL-31 is characterized by a four-helical-bundle structurecomprising helix A (amino acid residues 38-52), helix B (amino acidresidues 83-98), helix C (amino acid residues 104-117) and helix D(amino acid residues 137-152), as shown in SEQ ID NO:2. Thus, thepresent invention further provides fusion proteins encompassing: (a)polypeptide molecules comprising one or more of the helices describedabove; and (b) functional fragments comprising one or more of thesehelices. The other polypeptide portion of the fusion protein may becontributed by another four-helical-bundle cytokine, such as IL-15,IL-2, IL-4 and GM-CSF, or by a non-native and/or an unrelated secretorysignal peptide that facilitates secretion of the fusion protein.

The present invention also provides antibodies that bind to polypeptidefragments or peptides comprising an epitope-bearing portion of a IL-31polypeptide described herein. Such fragments or peptides may comprise an“immunogenic epitope,” which is a part of a protein that elicits anantibody response when the entire protein is used as an immunogen.Immunogenic epitope-bearing peptides can be identified using standardmethods (see, for example, Geysen et al., Proc. Nat'l Acad. Sci. USA81:3998 (1983)). The binding of the antibodies to these functionalfragments results in inhibition, blocking, neutralization, and/orreduction in signal transduction of IL-31 on its cognate receptor.

In contrast, polypeptide fragments or peptides may comprise an“antigenic epitope,” which is a region of a protein molecule to which anantibody can specifically bind. Certain epitopes consist of a linear orcontiguous stretch of amino acids, and the antigenicity of such anepitope is not disrupted by denaturing agents. It is known in the artthat relatively short synthetic peptides that can mimic epitopes of aprotein can be used to stimulate the production of antibodies againstthe protein (see, for example, Sutcliffe et al., Science 219:660(1983)). Accordingly, antigenic epitope-bearing peptides andpolypeptides of the present invention are useful to raise antibodies(e.g., neutralizing antibodies) that bind with the polypeptidesdescribed herein. Hopp/Woods hydrophilicity profiles can be used todetermine regions that have the most antigenic potential (Hopp et al.,1981, ibid. and Hopp, 1986, ibid.). For example, in human IL-31,hydrophilic regions include amino acid residues 54-59 of SEQ ID NO:2,amino acid residues 129-134 of SEQ ID NO:2, amino acid residues 53-58 ofSEQ ID NO:2, amino acid residues 35-40 of SEQ ID NO:2, and amino acidresidues 33-38 of SEQ ID NO:2. For example, in mouse IL-31, hydrophilicregions include amino acid residues 34-39 of SEQ ID NO:4, amino acidresidues 46-51 of SEQ ID NO:4, amino acid residues 131-136 of SEQ IDNO:4, amino acid residues 158-163 of SEQ ID NO:4, and amino acidresidues 157-162 of SEQ ID NO:4.

Antigenic epitope-bearing peptides and polypeptides preferably containat least four to ten amino acids, at least ten to fourteen amino acids,or about fourteen to about thirty amino acids of SEQ ID NO:2 or SEQ IDNO:4. Such epitope-bearing peptides and polypeptides can be produced byfragmenting a IL-31 polypeptide, or by chemical peptide synthesis, asdescribed herein. Moreover, epitopes can be selected by phage display ofrandom peptide libraries (see, for example, Lane and Stephen, Curr.Opin. Immunol. 5:268 (1993); and Cortese et al., Curr. Opin. Biotechnol.7:616 (1996)). Standard methods for identifying epitopes and producingantibodies from small peptides that comprise an epitope are described,for example, by Mole, “Epitope Mapping,” in Methods in MolecularBiology, Vol. 10, Manson (ed.), pages 105-116 (The Humana Press, Inc.1992); Price, “Production and Characterization of SyntheticPeptide-Derived Antibodies,” in Monoclonal Antibodies: Production,Engineering, and Clinical Application, Ritter and Ladyman (eds.), pages60-84 (Cambridge University Press 1995), and Coligan et al. (eds.),Current Protocols in Immunology, pages 9.3.1-9.3.5 and pages9.4.1-9.4.11 (John Wiley & Sons 1997).

The activity of the antibodies as described herein can be measured bytheir ability to inhibit, or reduce proliferation using a variety ofassays that measure proliferation of and/or binding to cells expressingthe IL-31RA receptor. Of particular interest are changes inIL-31-dependent cells. Suitable cell lines to be engineered to beIL-31-dependent include the IL-3-dependent BaF3 cell line (Palacios andSteinmetz, Cell 41: 727-734, 1985; Mathey-Prevot et al., Mol. Cell.Biol. 6: 4133-4135, 1986), FDC-P1 (Hapel et al., Blood 64: 786-790,1984), and MO7e (Kiss et al., Leukemia 7: 235-240, 1993). Growthfactor-dependent cell lines can be established according to publishedmethods (e.g. Greenberger et al., Leukemia Res. 8: 363-375, 1984; Dexteret al., in Baum et al. Eds., Experimental Hematology Today, 8th Ann.Mtg. Int. Soc. Exp. Hematol. 1979, 145-156, 1980).

The activity of the anti-IL-31 antibodies described herein can bemeasured by a silicon-based biosensor microphysiometer which measuresthe extracellular acidification rate or proton excretion associated withreceptor binding and subsequent physiologic cellular responses. Anexemplary device is the Cytosensor™ Microphysiometer manufactured byMolecular Devices, Sunnyvale, Calif. A variety of cellular responses,such as cell proliferation, ion transport, energy production,inflammatory response, regulatory and receptor activation, and the like,can be measured by this method. See, for example, McConnell, H. M. etal., Science 257:1906-1912, 1992; Pitchford, S. et al., Meth. Enzymol.228:84-108, 1997; Arimilli, S. et al., J. Immunol. Meth. 212:49-59,1998; Van Liefde, I. et al., Eur. J. Pharmacol. 346:87-95, 1998.

Antagonists are also useful as research reagents for characterizingsites of ligand-receptor interaction. Antagonists are useful to inhibitexpansion, proliferation, activation, and/or differentiation of cellsinvolved in regulating hematopoiesis. Inhibitors of IL-31 activity(IL-31 antagonists) include anti-IL-31 antibodies and soluble IL-31receptors, as well as other peptidic and non-peptidic agents (includingribozymes).

Inhibition the activity of IL-31 can be measured by a number of assays.In addition to those assays disclosed herein, samples can be tested forinhibition of IL-31 activity within a variety of assays designed tomeasure receptor binding, the stimulation/inhibition of IL-31-dependentcellular responses or proliferation of IL-31RA receptor-expressingcells.

A IL-31-binding polypeptide can also be used for purification of ligand.The polypeptide is immobilized on a solid support, such as beads ofagarose, cross-linked agarose, glass, cellulosic resins, silica-basedresins, polystyrene, cross-linked polyacrylamide, or like materials thatare stable under the conditions of use. Methods for linking polypeptidesto solid supports are known in the art, and include amine chemistry,cyanogen bromide activation, N-hydroxysuccinimide activation, epoxideactivation, sulfhydryl activation, and hydrazide activation. Theresulting medium will generally be configured in the form of a column,and fluids containing ligand are passed through the column one or moretimes to allow ligand to bind to the receptor polypeptide. The ligand isthen eluted using changes in salt concentration, chaotropic agents(guanidine HCl), or pH to disrupt ligand-receptor binding.

An assay system that uses a ligand-binding receptor (or an antibody, onemember of a complement/anti-complement pair) or a binding fragmentthereof, and a commercially available biosensor instrument (BIAcore,Pharmacia Biosensor, Piscataway, N.J.) may be advantageously employed.Such receptor, antibody, member of a complement/anti-complement pair orfragment is immobilized onto the surface of a receptor chip. Use of thisinstrument is disclosed by Karlsson, J. Immunol. Methods 145:229-40,1991 and Cunningham and Wells, J. Mol. Biol. 234:554-63, 1993. Areceptor, antibody, member or fragment is covalently attached, usingamine or sulfhydryl chemistry, to dextran fibers that are attached togold film within the flow cell. A test sample is passed through thecell. If a ligand, epitope, or opposite member of thecomplement/anti-complement pair is present in the sample, it will bindto the immobilized receptor, antibody or member, respectively, causing achange in the refractive index of the medium, which is detected as achange in surface plasmon resonance of the gold film. This system allowsthe determination of on- and off-rates, from which binding affinity canbe calculated, and assessment of stoichiometry of binding.Alternatively, ligand/receptor binding can be analyzed using SELDI™technology (Ciphergen, Inc., Palo Alto, Calif.).

IL-31 antibodies can be used to block the biological action ofpro-inflammatory IL-31 and are useful as anti-inflammatory therapeuticsin a variety of diseases as described herein. One of skill in the artwould recognize that antigenic, epitope-bearing polypeptides contain asequence of at least 6, preferably at least 9, and more preferably atleast 15 to about 30 contiguous amino acid residues of a IL-31polypeptide (e.g., SEQ ID NO:2). Polypeptides comprising a largerportion of a IL-31 polypeptide, i.e., from 30 to 100 residues up to theentire length of the amino acid sequence are included. Antigens orimmunogenic epitopes can also include attached tags, adjuvants, vehiclesand carriers, as described herein. Suitable antigens include the IL-31polypeptide encoded by SEQ ID NO:2 from amino acid number 24 to aminoacid number 164, or a contiguous 9 to 141 amino acid fragment thereof.Other suitable antigens include, the full length and the mature IL-31,helices A-D, and individual or multiple helices A, B, C, and D, of theIL-31 four-helical-bundle structure, as described herein. Preferredpeptides to use as antigens are hydrophilic peptides such as thosepredicted by one of skill in the art from a hydrophobicity plot, asdescribed herein, for example, amino acid residues 114-119, 101-105,126-131, 113-118, and 158-162 of SEQ ID NO:2; and amino acid residues34-39, 46-51, 131-136, 158-163 and 157-162 of SEQ ID NO:4. Moreover,IL-31 antigenic epitopes as predicted by a Jameson-Wolf plot, e.g.,using DNASTAR Protean program (DNASTAR, Inc., Madison, Wis.) serve aspreferred antigens, and are readily determined by one of skill in theart.

Antibodies from an immune response generated by inoculation of an animalwith these antigens can be isolated and purified as described herein.Methods for preparing and isolating polyclonal and monoclonal antibodiesare well known in the art. See, for example, Current Protocols inImmunology, Cooligan, et al. (eds.), National Institutes of Health, JohnWiley and Sons, Inc., 1995; Sambrook et al., Molecular Cloning: ALaboratory Manual, Second Edition, Cold Spring Harbor, N.Y., 1989; andHurrell, J. G. R., Ed., Monoclonal Hybridoma Antibodies: Techniques andApplications, CRC Press, Inc., Boca Raton, Fla., 1982.

As would be evident to one of ordinary skill in the art, polyclonalantibodies can be generated from inoculating a variety of warm-bloodedanimals such as horses, cows, goats, sheep, dogs, chickens, rabbits,mice, and rats with a IL-31 polypeptide or a fragment thereof. Theimmunogenicity of a IL-31 polypeptide may be increased through the useof an adjuvant, such as alum (aluminum hydroxide) or Freund's completeor incomplete adjuvant. Polypeptides useful for immunization alsoinclude fusion polypeptides, such as fusions of IL-31 or a portionthereof with an immunoglobulin polypeptide or with maltose bindingprotein. The polypeptide immunogen may be a full-length molecule or aportion thereof. If the polypeptide portion is “hapten-like”, suchportion may be advantageously joined or linked to a macromolecularcarrier (such as keyhole limpet hemocyanin (KLH), bovine serum albumin(BSA) or tetanus toxoid) for immunization.

Antibodies are considered to be specifically binding if: 1) they exhibita threshold level of binding activity, and 2) they do not significantlycross-react with related polypeptide molecules. A threshold level ofbinding is determined if anti-IL-31 antibodies herein bind to a IL-31polypeptide, peptide or epitope with an affinity at least 10-foldgreater than the binding affinity to control (non-IL-31) polypeptide. Itis preferred that the antibodies exhibit a binding affinity (K_(a)) of10⁶ M⁻¹ or greater, preferably 10⁷ M⁻¹ or greater, more preferably 10⁸M⁻¹ or greater, and most preferably 10⁹ M⁻¹ or greater. The bindingaffinity of an antibody can be readily determined by one of ordinaryskill in the art, for example, by Scatchard analysis (Scatchard, G.,Ann. NY Acad. Sci. 51: 660-672, 1949).

Whether anti-IL-31 antibodies do not significantly cross-react withrelated polypeptide molecules is shown, for example, by the antibodydetecting IL-31 polypeptide but not known related polypeptides using astandard Western blot analysis (Ausubel et al., ibid.). Examples ofknown related polypeptides are those disclosed in the prior art, such asknown orthologs, and paralogs, and similar known members of a proteinfamily. Screening can also be done using non-human IL-31, and IL-31mutant polypeptides. Moreover, antibodies can be “screened against”known related polypeptides, to isolate a population that specificallybinds to the IL-31 polypeptides. For example, antibodies raised to IL-31are adsorbed to related polypeptides adhered to insoluble matrix;antibodies specific to IL-31 will flow through the matrix under theproper buffer conditions. Screening allows isolation of polyclonal andmonoclonal antibodies non-crossreactive to known closely relatedpolypeptides (Antibodies: A Laboratory Manual, Harlow and Lane (eds.),Cold Spring Harbor Laboratory Press, 1988; Current Protocols inImmunology, Cooligan, et al. (eds.), National Institutes of Health, JohnWiley and Sons, Inc., 1995). Screening and isolation of specificantibodies is well known in the art. See, Fundamental Immunology, Paul(eds.), Raven Press, 1993; Getzoff et al., Adv. in Immunol. 43: 1-98,1988; Monoclonal Antibodies: Principles and Practice, Goding, J. W.(eds.), Academic Press Ltd., 1996; Benjamin et al., Ann. Rev. Immunol.2: 67-101, 1984. Specifically binding anti-IL-31 antibodies can bedetected by a number of methods in the art, and disclosed below.

Monoclonal antibodies can be prepared, for example, by immunizingSprague-Dawley Rats (Charles River Laboratories, Wilmington, Mass.),with the purified mature recombinant human IL-31 polypeptide (amino acidresidues 27 (Leu) to 167 (Thr) of SEQ ID NO:2) or the mouse ortholog,produced from the expression systems listed herein. The rats are eachgiven an initial intraperitoneal (IP) injection of 100 μg of thepurified human recombinant IL-31 protein in Complete Freund's Adjuvant(Pierce, Rockford, Ill.) followed by booster IP injections of 50 μg ofthe purified recombinant protein in Incomplete Freund's Adjuvant everytwo weeks. Seven to ten days after the administration of the thirdbooster injection, the animals are bled and the serum is collected.

The human IL-31-specific rat sera samples are characterized by ELISA fortiter to the specific antibody target biotinylated human IL-31.

Splenocytes and lymphatic node cells are harvested from 2 high-titerrats and fused to SP2/0 (mouse) myeloma cells using PEG 1500 in twoseparate fusion procedures (4:1 fusion ratio, splenocytes to myelomacells, “Antibodies A Laboratory Manual”, E. Harlow and D. Lane, ColdSpring Harbor Press). Following 10 days growth post-fusion, specificantibody-producing hybridoma pools are identified by ELISA. Hybridomapools positive in both ELISA protocols are analyzed further for theirability to block or reduce the receptor binding activity(“neutralization assay”) of purified recombinant IL-31.

Hybridoma pools yielding positive results by ELISA only or ELISA and the“neutralization assay” are cloned at least two times by limitingdilution.

Monoclonal antibodies purified from tissue culture media arecharacterized for their utility in an ELISA for the quantitativedetermination of recombinant and native human IL-31. The antibodies areselected and a quantitative assay is developed.

Monoclonal antibodies purified from tissue culture media arecharacterized for their ability to block or reduce the receptor bindingactivity (“neutralization assay”) of purified recombinant huIL-31 onBaF3/MPL-IL-31 cells. A number of “neutralizing” monoclonal antibodiesare identified in this manner. Hybridomas expressing the neutralizingmonoclonal antibodies to human IL-31 described can then be depositedwith the American Type Tissue Culture Collection (ATCC; Manassas Va.)patent depository as original deposits under the Budapest Treaty.

Monoclonal antibodies can be prepared by immunizing Lewis Rats (RocklandImmunochemicals, Gilbertsville, Pa.), with the cleaved and purifiedIL-31 recombinant fusion protein. The rats are each given an initialintraperitoneal (IP) injection of 100 μg of the purified recombinantfusion protein in Complete Freund's Adjuvant (Pierce, Rockford, Ill.)followed by booster IP injections of 50 μg of the purified recombinantprotein in Incomplete Freund's Adjuvant every two weeks for four weeks.Following the first four weeks of immunizations, booster LP injectionsof 50 ug of the cleaved purified recombinant protein coupled to thecarrier protein keyhole limpet hemocyanin (KLH, Pierce, Rockford, Ill.)in Incomplete Freund's are administered every two weeks for four weeks.Seven to ten days after the administration of the fourth boosterinjection, the animals are bled and the serum was collected. TheIL-31-specific rat serum samples are characterized by ELISA using 500ng/ml of the purified recombinant fusion protein IL-31-Fc as thespecific antibody target and an unrelated fusion protein as anon-specific antibody target. Splenocytes are harvested from one or morehigh-titer rats and fused to SP2/0 (mouse) myeloma cells in an optimizedPEG-mediated fusion protocol (Rockland Immunochemicals). Following 12days growth post-fusion, specific antibody-producing hybridoma pools areidentified by ELISA using 500 ng/ml each of the purified IL-31recombinant fusion protein as the specific antibody target and anunrelated fusion protein as a non-specific antibody target. Hybridomapools positive to the specific antibody target only are analyzed furtherfor their ability to block or reduce the receptor binding activity(“neutralization assay”) of recombinant hulL-31 on BaF3/MPL-IL-31 cellsand an ability to bind via FACS analysis as antibody target. Hybridomapools yielding a specific positive result in the ELISA assay andpositive results in either the FACS or “neutralization assay” are clonedat least two times by limiting dilution.

Five rat anti-mouse hybridomas were generated in a similar fashion andwere given the following clone designations: clone 271.9.4.2.6, clone271.26.6.6.1, clone 271.33.1.2.2, clone 271.33.3.2.1, and clone271.39.4.6.5. See Example 1. The monoclonal antibodies produced by theseclones were characterized in a number of ways including binning (i.e,determining if each antibody could inhibit the binding of any otherbinding), relative affinity, and neutralization. The monoclonalantibodies appear to fall into two separate bins with clone 271.33.3.2.1binding to a separate epitope than the other four. Relative bindingaffinity for four of these monoclonal antibodies is described in Example14.

Binding affinity of the monoclonal antibodies can be generated.Goat-anti-Rat IgG-Fc gamma specific Antibody (Jackson) is immobilizedonto a CM5 Biacore chip. The assay is optimized to bind each mAb ontothe anti-Rat capture surface and then a concentration series of IL-31 isinjected across the mAb to see association (Ka) and dissociation (Kd).After each run, the surface is regenerated back to the anti-Rat Antibodywith 2 injections of 20 mM HCl. Data is generated for each andevaluation software (BIAevaluation software version 3.2, PharmaciaBIAcore, Uppsala, Sweden) is used to assess the kinetics of theanti-IL-31 antibody binding to the IL-31 protein.

Murine anti-human Il-31 mAbs can be generated as follows. Six to twelveweek old IL-31 knockout mice are immunized by intraperitoneal injectionwith 25-50 ug of soluble human IL-31-muFc protein) mixed 1:1 (v:v) withRibi adjuvant (Sigma) on a biweekly schedule. Seven to ten daysfollowing the third immunization, blood samples are taken viaretroorbital bleed, the serum harvested and evaluated for its ability toinhibit the binding of IL-31 in neutralization assays (e.g., describedherein) and to stain IL-31 transfected versus untransfected 293 cells ina FACS staining assay. Mice continued to be immunized and blood samplestaken and evaluated as described above until neutralization titersreaches a plateau. At that time, mice with the highest neutralizationtiters are injected intravascularly with 25-50 ug of soluble IL-31-Fcprotein in PBS. Three days later, the spleen and lymph nodes from thesemice are harvested and used for hybridoma generation, for example usingmouse myeloma (P3-X63-Ag8.653.3.12.11) cells or other appropriate celllines in the art, using standard methods known in the art (e.g., seeKearney, J. F. et al., J Immunol. 123:1548-50, 1979; and Lane, R. D. JImmunol Methods 81:223-8, 1985).

Primary screening can be performed on the hybridoma supernatants at 8-10days post-fusion for their ability to bind IL-31-muFc protein by ELISAusing HRP-conjugated goat anti-mouse kappa and anti-lambda light chainsecond step reagents to identify bound mouse antibodies.

Biochemical confirmation that the target molecule, IL-31, recognized bythe putative anti-IL-31 mAbs is indeed IL-31 are performed by standardimmunoprecipitation followed by SDS-PAGE analysis or western blottingprocedures, both employing soluble membrane preparations from IL-31transfected versus untransfected Baf3 cells. The mAbs are tested fortheir ability to specifically immunoprecipitate or western blot thesoluble IL-31-muFc protein.

Monoclonal antibodies purified from tissue culture media werecharacterized for their ability to block or inhibit the ability of IL-31to bind to its receptor in a neutralization assay. Twenty “neutralizing”monoclonal antibodies were identified in this manner. Ten of these havebeen identified as “good neutralizers” after the first round cloning:clone 292.72.3, clone 292.118.6, clone 292.63.5, clone 292.64.6, clone292.84.1, clone 292.109.4, clone 292.12.3, clone 292.51.5, clone292.39.5, and clone 292.105.4. The other ten have the following clonedesignations after the first round of cloning: clone 294.35.2, clone294.146.5, clone 292.152.4, clone 292.154.4, clone 294.154.5, clone294.35.3, clone 291.78.4, clone 294.155.6, clone 294.158.5, clone294.163.2, and clone 294.144.3.

The specified monoclonal antibodies were taken through a second round ofcloning and, again, characterized for their ability to block or inhibitthe ability of IL-31 to bind to its receptor in a neutralization assay.The clone designations after the second round of cloning for the “goodneutralizers” are: clone 292.12.3.1, clone 292.63.5.3, clone 292.72.3.1,clone 292.84.1.6, clone 292.118.6.4, clone 292.64.6.5.5, clone292.39.5.3, clone 292.51.5.2, clone 292.109.4.4, and clone 292.105.4.1.Six of the other ten have the following clone designations: clone292.152.4.1, clone 294.158.5.2, clone 294.32.2.6.3, clone 294.144.3.5,clone 294.154.5.3, and clone 294.163.2.1.

Hybridomas expressing the neutralizing monoclonal antibodies to humanIL-31 described above were deposited with the American Type TissueCulture Collection (ATCC; located at 10801 University Blvd., Manassas,Va. 20110-2209 USA) patent depository as original deposits under theBudapest Treaty and were given the following ATCC Accession No.s.: clone292.12.3.1 (ATCC Patent Deposit Designation PTA-6815; deposited on Jun.29, 2005); clone 292.72.3.1 (ATCC Patent Deposit Designation PTA-6816;deposited on Jun. 29, 2005); clone 292.63.5.3 (ATCC Patent DepositDesignation PTA-6829; deposited on Jul. 6, 2005); clone 292.118.6.4(ATCC Patent Deposit Designation PTA-6830; deposited on Jul. 6, 2005);clone 294.163.2.1 (ATCC Patent Deposit Designation PTA-6831; depositedon Jul. 6, 2005); clone 292.84.1.6 (ATCC Patent Deposit DesignationPTA-6871; deposited on Jul. 19, 2005); clone 294.35.2.6.3 (ATCC PatentDeposit Designation PTA-6872; deposited on Jul. 19, 2005); clone294.154.5.6 ATCC Patent Deposit Designation PTA-6875; deposited on Jul.19, 2005); and clone 294.144.3.5 (ATCC Patent Deposit DesignationPTA-6873; deposited on Jul. 19, 2005).

A hybridoma expressing the neutralizing monoclonal antibodies to mouseIL-31 described herein was deposited with the American Type TissueCulture Collection (ATCC; located at University Blvd., Manassas, Va.20110-2209 USA) patent depository as an original deposit under theBudapest Treaty and was given the following ATCC Accession No.s.: clone271.26.6.6.1 (ATCC Patent Deposit Designation PTA-6874; deposited onJul. 19, 2005).

The monoclonal antibodies produced by these hybridoma clones can becultured in a growth medium of 90% Iscove's Modified Dulbecco's mediumwith 2 mM L-glutamine, 100 μg/mL penicillin, and 100 μg/mL streptomycinsulfate, and 10% Fetal Clone I Serum (Hyclone Laboratories). The clonescan be propogated by starting cultures at 2×10⁵ cells/ml and maintainingbetween 1×10⁵ and 5×10⁵ cell/ml at 37° C. and 5-6% CO. Cells can beadapted to serum free conditions upon subsequent transfers. Cells thatare frozen are stored in 90% serum, 10% DMSO and stored in vapor phaseof liquid nitrogen freezer.

Monoclonal antibodies in tissue culture media are characterized fortheir ability to block, inhibit, prevent, or reduce receptor bindingwhen grown in the presence of the purified recombinant proteins humanIL-31. For example, the monoclonal antibodies produced by these cloneswere characterized in a number of ways including binning (i.e,determining if each antibody could inhibit the binding of any otherbinding), relative affinity, and neutralization. The ten goodneutralizing antibodies appear to be in the same bin, with the othermonoclonal antibodies grouping into three separate bins. In addition,eight of the good neutralizing antibodies are IgG1 isotype and the othertwo are IgG2a isotype.

Monoclonal antibodies from hybridoma supernatants were captured usinggoat goat anti murine Fc pAb and the apparent binding binding affinity(EC50) of biotinylated IL31 was measured. Under these assay conditions,the good neutralizers have the lowest and comparable EC50 values ˜4ng/mL Bt-IL31. The apparent affinity of the weak neutralizers spans arange from ˜10 ng/mL to 236 ng/mL Bt-IL31.

Monoclonal antibodies generated by the methods described herein can betested for neutralization by a variety of methods. For example theluciferase assay as described in published U.S. patent application (Seepublication number 20030224487, Sprecher, Cindy et al., 2003) can beused. In addition neutralization can be tested by measuring a decreasein the production of pro-inflammatory chemokines such as TARC and MDCfrom keratinocyte cultures in the presence of ligand and the monoclonalantibody. Neutralization can also be measured by the in vivo modelsdescribed herein.

In one embodiment, the antibodies of the present invention are humanantigen-binding antibody fragments of the present invention and include,but are not limited to, Fab, Fab′ and F(ab′)2, Fd, single-chain Fvs(scFv), single-chain antibodies, disulfide-linked Fvs (sdFv) andfragments comprising either a VL or VH domain. Antigen-binding antibodyfragments, including single-chain antibodies, may comprise the variableregion(s) alone or in combination with the entirety or a portion of thefollowing: hinge region, C_(H1), C_(H2), and C_(H3) domains. Alsoincluded in the invention are antigen-binding fragments also comprisingany combination of variable region(s) with a hinge region, C_(H1),C_(H2), and C_(H3) domains.

In another embodiment, the antibodies of the present invention may bemonospecific, bispecific, trispecific or of greater multispecificity.Multispecific antibodies may be specific for different epitopes of apolypeptide of the present invention or may be specific for both apolypeptide of the present invention as well as for a heterologousepitope, such as a heterologous polypeptide or solid support material.See, e.g., PCT publications WO 93/17715; WO 92/08802; WO 91/00360; WO92/05793; Tutt, et al., J. Immunol. 147:60-69 (1991); U.S. Pat. Nos.4,474,893; 4,714,681; 4,925,648; 5,573,920; 5,601,819; Kostelny et al.,J. Immunol. 148:1547-1553 (1992).

The present invention also includes genetically altered antibodies thatare functionally equivalent to the above-described antibodies. Modifiedantibodies providing improved stability and/or therapeutic efficacy arepreferred. Examples of modified antibodies include those withconservative substitutions of amino acid residues, and one or moredeletions or additions of amino acids which do not significantlydeleteriously alter the antigen binding utility. Substitutions can rangefrom changing or modifying one or more amino acid residues to completeredesign of a region as long as the therapeutic utility is maintained.Antibodies of the present invention can be can be modifiedpost-translationally (e.g., acetylation, and phosphorylation) or can bemodified synthetically (e.g., the attachment of a labeling group).

The genetically altered antibodies also include chimeric antibodies thatderived from the anti-IL-31 antibodies. The chimeric antibodies comprisea variable region derived from a mouse or rat and a constant regionderived from a human so that the chimeric antibody has a longerhalf-life and is less immunogenic when administered to a human subject.The method of making chimeric antibodies is known in the art. Thevariable regions of these antibodies can be connected with a constantregion of a human IgG to form the desired chimeric antibody.

The genetically altered anti-IL-31 antibodies used in the presentinvention include humanized version of the antibodies described herein.Humanized antibodies comprise CDRs of a mouse donor immunoglobulin andheavy chain and light chain frameworks of a human acceptorimmunoglobulin. The method of making humanized antibody is disclosed inU.S. Pat. Nos. 5,301,101; 5,585,089; 5,693,762; and 6,180,370 (each ofwhich is incorporated by reference in its entirety). The CDRs of theseantibodies can then be grafted to any selected human frameworks, whichare known in the art, to generate the desired humanized antibody.

Antibodies of the present invention may be described or specified interms of the epitope(s) or portion(s) of a polypeptide of the presentinvention that they recognize or specifically bind. The epitope(s) orpolypeptide portion(s) may be specified as described herein, e.g., byN-terminal and C-terminal positions, by size in contiguous amino acidresidues, or listed in the Tables and FIGS. Antibodies that specificallybind any epitope or polypeptide of the present invention may also beexcluded. Therefore, the present invention includes antibodies thatspecifically bind polypeptides of the present invention, and allows forthe exclusion of the same.

The invention also provides antibodies that competitively inhibit thebinding of a monoclonal antibody to a polypeptide of the invention,preferably the polypeptide of SEQ ID NO:2 or SEQ ID NO: 4. Competitiveinhibition can be determined by any method known in the art, forexample, using the competitive binding assays described herein. Inpreferred embodiments, the antibody competitively inhibits the bindingof a monoclonal antibody of the invention by at least 90%, at least 80%,at least 70%, at least 60%, or at least 50% to the polypeptide of SEQ IDNO:2 or SEQ ID NO: 4.

The invention also provides antibodies that competitively inhibitbinding of an antibody to an epitope of the invention as determined byany method known in the art for determining competitive binding, forexample, the immunoassays described herein. In preferred embodiments,the antibody competitively inhibits binding to the epitope by at least90%, at least 80%, at least 70%, at least 60%, or at least 50%.

The antibodies of the present invention include derivatives that aremodified, i.e, by the covalent attachment of any type of molecule to theantibody such that covalent attachment does not prevent the antibodyfrom generating an anti-idiotypic response. For example, but not by wayof limitation, the antibody derivatives include antibodies that havebeen modified, e.g., by glycosylation, acetylation, pegylation,phosphylation, amidation, derivatization by known protecting/blockinggroups, proteolytic cleavage, linkage to a cellular ligand or otherprotein, etc. Any of numerous chemical modifications may be carried outby known techniques, including, but not limited to specific chemicalcleavage, acetylation, formylation, metabolic synthesis of tunicamycin,etc. Additionally, the derivative may contain one or more non-classicalamino acids.

The antibodies of the present invention also encompass antibodies orfragments thereof that have half-lives (e.g., serum half-lives) in amammal, preferably a human, of greater than 15 days, preferably greaterthan 20 days, greater than 25 days, greater than 30 days, greater than35 days, greater than 40 days, greater than 45 days, greater than 2months, greater than 3 months, greater than 4 months, or greater than 5months. The increased half-lives of the antibodies of the presentinvention or fragments thereof in a mammal, preferably a human, resultin a higher serum titer of said antibodies or antibody fragments in themammal, and thus, reduce the frequency of the administration of saidantibodies or antibody fragments and/or reduces the concentration ofsaid antibodies or antibody fragments to be administered.

Antibodies or fragments thereof having increased in vivo half-lives canbe generated by techniques known to those of skill in the art. Forexample, antibodies or fragments thereof with increased in vivohalf-lives can be generated by modifying (e.g., substituting, deletingor adding) amino acid residues identified as involved in the interactionbetween the Fc domain and the FcRn receptor (see, e.g., InternationalPublication Nos. WO 97/34631 and WO 02/060919, which are incorporatedherein by reference in their entireties). Antibodies or fragmentsthereof with increased in vivo half-lives can be generated by attachingto said antibodies or antibody fragments polymer molecules such as highmolecular weight polyethyleneglycol (PEG). PEG can be attached to saidantibodies or antibody fragments with or without a multifunctionallinker either through site-specific conjugation of the PEG to the N- orC-terminus of said antibodies or antibody fragments or via epsilon-aminogroups present on lysine residues. Linear or branched polymerderivatization that results in minimal loss of biological activity willbe used. The degree of conjugation will be closely monitored by SDS-PAGEand mass spectrometry to ensure proper conjugation of PEG molecules tothe antibodies. Unreacted PEG can be separated from antibody-PEGconjugates by, e.g., size exclusion or ion-exchange chromatography.

It is understood that the humanized antibodies designed by the presentmethod may have additional conservative amino acid substitutions whichhave substantially no effect on antigen binding or other immunoglobulinfunctions. By conservative substitutions is intended combinations suchas gly, ala; val, ile, leu; asp, glu; asn, gin; ser, thr; lys, arg; andphe, tyr.

Methods for humanizing non-human antibodies are well known in the art.Generally, humanized immunoglobulins, including humanized antibodies,have been constructed by means of genetic engineering. Most humanizedimmunoglobulins that have been previously described (Jones et al., op.cit.; Verhoeyen et al., op. cit.; Riechmann et al., op. cit.) havecomprised a framework that is identical to the framework of a particularhuman immunoglobulin chain, the acceptor, and three CDR's from anon-human donor immunoglobulin chain. Specifically, humanized antibodiesare antibody molecules from non-human species antibody that binds thedesired antigen having one or more complementarity determining regions(CDRs) from the non-human species and framework regions from a humanimmunoglobulin molecule.

The present invention includes criteria by which a limited number ofamino acids in the framework of a humanized immunoglobulin chain arechosen to be the same as the amino acids at those positions in the donorrather than in the acceptor, in order to increase the affinity of anantibody comprising the humanized immunoglobulin chain.

The antibodies of the present invention are generated based in part onthe model that two contributing causes of the loss of affinity in priormeans of producing humanized antibodies (using as examples mouseantibodies as the source of CDR's) are:

(1) When the mouse CDR's are combined with the human framework, theamino acids in the framework close to the CDR's become human instead ofmouse. Without intending to be bound by theory, these changed aminoacids may slightly distort the CDR's, because they create differentelectrostatic or hydrophobic forces than in the donor mouse antibody,and the distorted CDR's may not make as effective contacts with theantigen as the CDR's did in the donor antibody; and

(2) Amino acids in the original mouse antibody that are close to, butnot part of, the CDR's (i.e., still part of the framework), may makecontacts with the antigen that contribute to affinity. These amino acidsare lost when the antibody is humanized, because all framework aminoacids are made human.

To avoid these problems, and to produce humanized antibodies that have avery strong affinity for a desired antigen, the present invention usesone or more of the following principles for designing humanizedimmunoglobulins. Also, the criteria may be used singly, or whennecessary in combination, to achieve the desired affinity or othercharacteristics.

A principle is that as acceptor, a framework is used from a particularhuman immunoglobulin that is unusually homologous to the donorimmunoglobulin to be humanized, or use a consensus framework from manyhuman antibodies. For example, comparison of the sequence of a mouseheavy (or light) chain variable region against human heavy (or light)variable regions in a data bank (for example, the National BiomedicalResearch Foundation Protein Identification Resource) shows that theextent of homology to different human regions varies greatly, typicallyfrom about 40% to about 60-70%. By choosing as the acceptorimmunoglobulin one of the human heavy (respectively light) chainvariable regions that is most homologous to the heavy (respectivelylight) chain variable region of the donor immunoglobulin, fewer aminoacids will be changed in going from the donor immunoglobulin to thehumanized immunoglobulin. Hence, and again without intending to be boundby theory, it is believed that there is a smaller chance of changing anamino acid near the CDR's that distorts their conformation. Moreover,the precise overall shape of a humanized antibody comprising thehumanized immunoglobulin chain may more closely resemble the shape ofthe donor antibody, also reducing the chance of distorting the CDR's.

Typically, one of the 3-5 most homologous heavy chain variable regionsequences in a representative collection of at least about 10 to 20distinct human heavy chains will be chosen as acceptor to provide theheavy chain framework, and similarly for the light chain. Preferably,one of the 1-3 most homologous variable regions will be used. Theselected acceptor immunoglobulin chain will most preferably have atleast about 65% homology in the framework region to the donorimmunoglobulin.

In many cases, it may be considered preferable to use light and heavychains from the same human antibody as acceptor sequences, to be surethe humanized light and heavy chains will make favorable contacts witheach other. In this case, the donor light and heavy chains will becompared only against chains from human antibodies whose completesequence is known, e.g., the Eu, Lay, Pom, Wol, Sie, Gal, Ou and WEAantibodies (Kabat et al., op. cit.; occasionally, the last few aminoacids of a human chain are not known and must be deduced by homology toother human antibodies). The human antibody will be chosen in which thelight and heavy chain variable regions sequences, taken together, areoverall most homologous to the donor light and heavy chain variableregion sequences. Sometimes greater weight will be given to the heavychain sequence. The chosen human antibody will then provide both lightand heavy chain acceptor sequences. In practice, it is often found thatthe human Eu antibody will serve this role.

According to the so-called “best-fit” method, the sequence of thevariable domain of a rodent antibody is screened against the entirelibrary of known human variable-domain sequences. The human sequencewhich is closest to that of the rodent is then accepted as the humanframework (FR) for the humanized antibody (Sims et al., J. Immunol.,151: 2296 (1993); Chothia et al., J. Mol. Biol., 196: 901 (1987)).Another method uses a particular framework derived from the consensussequence of all human antibodies of a particular subgroup of light orheavy chains. The same framework may be used for several differenthumanized antibodies (Carter et al., Proc. Natl. Acad. Sci. USA, 89:4285 (1992); Presta et al., J. Immunol., 151: 2623 (1993)).

Regardless of how the acceptor immunoglobulin is chosen, higher affinitymay be achieved by selecting a small number of amino acids in theframework of the humanized immunoglobulin chain to be the same as theamino acids at those positions in the donor rather than in the acceptor.Often, framework residues in the human framework regions will besubstituted with the corresponding residue from the CDR donor antibodyto alter, preferably improve, antigen binding. These frameworksubstitutions are identified by methods well known in the art, e.g., bymodeling of the interactions of the CDR and framework residues toidentify framework residues important for antigen binding and sequencecomparison to identify unusual framework residues at particularpositions. (See, e.g., Queen et al., U.S. Pat. No. 5,585,089; Riechmannet al., Nature 332:323 (1988), which are incorporated herein byreference in their entireties.) Antibodies can be humanized using avariety of techniques known in the art including, for example,CDR-grafting (EP 239,400; PCT publication WO 91/09967; U.S. Pat. Nos.5,225,539; 5,530,101; and 5,585,089), veneering or resurfacing (EP592,106; EP 519,596; Padlan, Molecular Immunology 28(4/5):489-498(1991); Studnicka et al., Protein Engineering 7(6):805-814 (1994);Roguska. et al., PNAS 91:969-973 (1994)), and chain shuffling (U.S. Pat.No. 5,565,332). Accordingly, such “humanized” antibodies are chimericantibodies (U.S. Pat. No. 4,816,567) wherein substantially less than anintact human variable domain has been substituted by the correspondingsequence from a non-human species.

A second principle is that the following categories define what aminoacids may be selected from the donor. Preferably, at many or all aminoacid positions in one of these categories, the donor amino acid will infact be selected.

Category 1: The amino acid position is in a CDR is defined by Kabat etal., op. cit.

Category 2: If an amino acid in the framework of the human acceptorimmunoglobulin is unusual (i.e., “rare”, which as used herein indicatesan amino acid occurring at that position in less than about 20% butusually less than about 10% of human heavy (respectively light) chain Vregion sequences in a representative data bank), and if the donor aminoacid at that position is typical for human sequences (i.e., “common”,which as used herein indicates an amino acid occurring in more thanabout 25% but usually more than about 50% of sequences in arepresentative data bank), then the donor amino acid rather than theacceptor may be selected. This criterion helps ensure that an atypicalamino acid in the human framework does not disrupt the antibodystructure. Moreover, by replacing an unusual amino acid with an aminoacid from the donor antibody that happens to be typical for humanantibodies, the humanized antibody may be made less immunogenic. Allhuman light and heavy chain variable region sequences are respectivelygrouped into “subgroups” of sequences that are especially homologous toeach other and have the same amino acids at certain critical positions(Kabat et al., op. cit.). When deciding whether an amino acid in a humanacceptor sequence is “rare” or “common” among human sequences, it willoften be preferable to consider only those human sequences in the samesubgroup as the acceptor sequence.

Category 3: In the positions immediately adjacent to one or more of the3 CDR's in the primary sequence of the humanized immunoglobulin chain,the donor amino acid(s) rather than acceptor amino acid may be selected.These amino acids are particularly likely to interact with the aminoacids in the CDR's and, if chosen from the acceptor, to distort thedonor CDR's and reduce affinity. Moreover, the adjacent amino acids mayinteract directly with the antigen (Amit et al., Science, 233, 747-753(1986), which is incorporated herein by reference) and selecting theseamino acids from the donor may be desirable to keep all the antigencontacts that provide affinity in the original antibody.

Category 4: A 3-dimensional model, typically of the original donorantibody, shows that certain amino acids outside of the CDR's are closeto the CDR's and have a good probability of interacting with amino acidsin the CDR's by hydrogen bonding, Van der Waals forces, hydrophobicinteractions, etc. At those amino acid positions, the donorimmunoglobulin amino acid rather than the acceptor immunoglobulin aminoacid may be selected. Amino acids according to this criterion willgenerally have a side chain atom within about 3 angstrom units of someatom in the CDR's and must contain an atom that could interact with theCDR atoms according to established chemical forces, such as those listedabove.

In the case of atoms that may form a hydrogen bond, the 3 angstroms ismeasured between their nuclei, but for atoms that do not form a bond,the 3 angstroms is measured between their Van der Waals surfaces. Hence,in the latter case, the nuclei must be within about 6 angstroms (3+sumof the Van der Waals radii) for the atoms to be considered capable ofinteracting. In many cases the nuclei will be from 4 or 5 to 6. ANG.apart. In determining whether an amino acid can interact with the CDRs,it is preferred not to consider the last 8 amino acids of heavy chainCDR 2 as part of the CDRs, because from the viewpoint of structure,these 8 amino acids behave more as part of the framework.

Amino acids in the framework that are capable of interacting with aminoacids in the CDR's, and which therefore belong to Category 4, may bedistinguished in another way. The solvent accessible surface area ofeach framework amino acid is calculated in two ways: (1) in the intactantibody, and (2) in a hypothetical molecule consisting of the antibodywith its CDRs removed. A significant difference between these numbers ofabout 10 square angstroms or more shows that access of the frameworkamino acid to solvent is at least partly blocked by the CDRs, andtherefore that the amino acid is making contact with the CDRs. Solventaccessible surface area of an amino acid may be calculated based on a3-dimensional model of an antibody, using algorithms known in the art(e.g., Connolly, J. Appl. Cryst. 16, 548 (1983) and Lee and Richards, J.Mol. Biol. 55, 379 (1971), both of which are incorporated herein byreference). Framework amino acids may also occasionally interact withthe CDR's indirectly, by affecting the conformation of another frameworkamino acid that in turn contacts the CDR's.

The amino acids at several positions in the framework are known to becapable of interacting with the CDRs in many antibodies (Chothia andLesk, J. Mol. Biol. 196, 901 (1987), Chothia et al., Nature 342, 877(1989), and Tramontano et al., J. Mol. Biol. 215, 175 (1990), all ofwhich are incorporated herein by reference), notably at positions 2, 48,64 and 71 of the light chain and 26-30, 71 and 94 of the heavy chain(numbering according to Kabat, op. cit.), and therefore these aminoacids will generally be in Category 4. Typically, humanizedimmunoglobulins, of the present invention will include donor amino acids(where different) in category 4 in addition to these. The amino acids atpositions 35 in the light chain and 93 and 103 in the heavy chain arealso likely to interact with the CDRs. At all these numbered positions,choice of the donor amino acid rather than the acceptor amino acid (whenthey differ) to be in the humanized immunoglobulin is preferred. On theother hand, certain positions that may be in Category 4 such as thefirst 5 amino acids of the light chain may sometimes be chosen from theacceptor immunoglobulin without loss of affinity in the humanizedimmunoglobulin. Chothia and Lesk (op. cit.) define the CDRs differentlyfrom Kabat et al. (op. cit.). Notably, CDR1 is defined as includingresidues 26-32. Accordingly, Riechmann et al., (op. cit.) chose theseamino acids from the donor immunoglobulins.

It is also important that antibodies be humanized with retention of highaffinity for the antigen and other favorable biological properties. Toachieve this goal, according to a preferred method, humanized antibodiesare prepared by a process of analysis of the parental sequences andvarious conceptual humanized products using three-dimensional models ofthe parental and humanized sequences. Computer programs are availablewhich illustrate and display probable three-dimensional conformationalstructures of selected candidate immunoglobulin sequences. Inspection ofthese displays permits analysis of the likely role of the residues inthe functioning of the candidate immunoglobulin sequence, i.e., theanalysis of residues that influence the ability of the candidateimmunoglobulin to bind its antigen. In this way, FR residues can beselected and combined from the recipient and import sequences so thatthe desired antibody characteristic, such as increased affinity for thetarget antigen(s), is achieved. In general, the CDR residues aredirectly and most substantially involved in influencing antigen binding.Computer programs to create models of proteins such as antibodies aregenerally available and well known to those skilled in the art (see,Levy et al., Biochemistry, 28, 7168-7175 (1989); Bruccoleri et al.,Nature, 335, 564-568 (1988); Chothia et al., Science, 233, 755-758(1986), all of which are incorporated herein by reference). These do notform part of the invention. Indeed, because all antibodies have similarstructures, the known antibody structures, which are available from theBrookhaven Protein Data Bank, can be used if necessary as rough modelsof other antibodies. Commercially available computer programs can beused to display these models on a computer monitor, to calculate thedistance between atoms, and to estimate the likelihood of differentamino acids interacting (see, Ferrin et al., J. Mol. Graphics, 6, 13-27(1988)).

In addition to the above categories, which describe when an amino acidin the humanized immunoglobulin may be taken from the donor, certainamino acids in the humanized immunoglobulin may be taken from neitherthe donor nor acceptor, if then fall in:

Category 5: If the amino acid at a given position in the donorimmunoglobulin is “rare” for human sequences, and the amino acid at thatposition in the acceptor immunoglobulin is also “rare” for humansequences, as defined above, then the amino acid at that position in thehumanized immunoglobulin may be chosen to be some amino acid “typical”of human sequences. A preferred choice is the amino acid that occursmost often at that position in the known human sequences belonging tothe same subgroup as the acceptor sequence.

Humanized antibodies generally have at least three potential advantagesover mouse or in some cases chimeric antibodies for use in humantherapy:

(1) Because the effector portion is human, it may interact better withthe other parts of the human immune system (e.g., destroy the targetcells more efficiently by complement-dependent cytotoxicity (CDC) orantibody-dependent cellular cytotoxicity (ADCC)).

(2) The human immune system should not recognize the framework orconstant region of the humanized antibody as foreign, and therefore theantibody response against such an injected antibody should be less thanagainst a totally foreign mouse antibody or a partially foreign chimericantibody.

(3) Injected mouse antibodies have been reported to have a half-life inthe human circulation much shorter than the half-life of normalantibodies (D. Shaw et al., J. Immunol., 138, 4534-4538 (1987)).Injected humanized antibodies will presumably have a half-life moresimilar to naturally occurring human antibodies, allowing smaller andless frequent doses to be given.

In one aspect, the present invention is directed to designing humanizedantibodies that are produced by expressing recombinant DNA segmentsencoding the heavy and light chain CDR's from a donor immunoglobulincapable of binding to a desired antigen, such as IL-31, attached to DNAsegments encoding acceptor human framework regions.

The DNA segments will typically further include an expression controlDNA sequence operably linked to the humanized immunoglobulin codingsequences, including naturally-associated or heterologous promoterregions. The expression control sequences will be eukaryotic promotersystems in vectors capable of transforming or transfecting eukaryotichost cells, but control sequences for prokaryotic hosts may also beused. Once the vector has been incorporated into the appropriate host,the host is maintained under conditions suitable for high levelexpression of the nucleotide sequences, and, as desired, the collectionand purification of the humanized light chains, heavy chains,light/heavy chain dimers or intact antibodies, binding fragments orother immunoglobulin forms may follow (see, S. Beychok, Cells ofImmunoglobulin Synthesis, Academic Press, N.Y., (1979), which isincorporated herein by reference).

Human constant region DNA sequences can be isolated in accordance withwell known procedures from a variety of human cells, but preferablyimmortalized B-cells (see, Kabat op. cit. and WP87/02671). The CDR's forproducing the immunoglobulins of the present invention will be similarlyderived from monoclonal antibodies capable of binding to thepredetermined antigen, such as IL-31, and produced by well known methodsin any convenient mammalian source including, mice, rats, rabbits, orother vertebrates, capable of producing antibodies. Suitable sourcecells for the constant region and framework DNA sequences, and hostcells for immunoglobulin expression and secretion, can be obtained froma number of sources, such as the American Type Culture Collection(“Catalogue of Cell Lines and Hybridomas,” sixth edition (1988)Rockville, Md. U.S.A., which is incorporated herein by reference).

In addition to the humanized immunoglobulins specifically describedherein, other “substantially homologous” modified immunoglobulins to thenative sequences can be readily designed and manufactured utilizingvarious recombinant DNA techniques well known to those skilled in theart. A variety of different human framework regions may be used singlyor in combination as a basis for the humanized immunoglobulins of thepresent invention. In general, modifications of the genes may be readilyaccomplished by a variety of well-known techniques, such assite-directed mutagenesis (see, Gillman and Smith, Gene, 8, 81-97 (1979)and S. Roberts et al., Nature, 328, 731-734 (1987), both of which areincorporated herein by reference).

The humanized antibodies of the invention include fragments as well asintact antibodies. Typically, these fragments compete with the intactantibody from which they were derived for antigen binding. The fragmentstypically bind with an affinity of at least 10⁷ M.⁻¹, and more typically10⁸ or 10⁹ M.⁻¹ (i.e., within the same ranges as the intact antibody).Humanized antibody fragments include separate heavy chains, light chainsFab, Fab′ F(ab′)₂, and Fv. Fragments are produced by recombinant DNAtechniques, or by enzymic or chemical separation of intactimmunoglobulins.

For further details in humanizing antibodies, see European Patent Nos.EP 239,400, EP 592,106, and EP 519,596; International Publication Nos.WO 91/09967 and WO 93/17105; U.S. Pat. Nos. 5,225,539, 5,530,101,5,565,332, 5,585,089, 5,766,886, and 6,407,213; and Padlan, 1991,Molecular Immunology 28(4/5): 489 498; Studnicka et al., 1994, ProteinEngineering 7(6): 805 814; Roguska et al., 1994, PNAS 91: 969 973; Tanet al., 2002, J. Immunol. 169: 1119 25; Caldas et al., 2000, ProteinEng. 13: 353 60; Morea et al., 2000, Methods 20: 267 79; Baca et al.,1997, J. Biol. Chem. 272: 10678 84; Roguska et al., 1996, Protein Eng.9: 895 904; Couto et al., 1995, Cancer Res. 55 (23 Supp): 5973s 5977s;Couto et al., 1995, Cancer Res. 55: 1717 22; Sandhu, 1994, Gene 150: 40910; Pedersen et al., 1994, J. Mol. Biol. 235: 959 73; Jones et al.,1986, Nature 321: 522-525; Reichmann et al., 1988, Nature 332: 323-329;and Presta, 1992, Curr. Op. Struct. Biol. 2: 593-596.

Various techniques have been developed for the production of antibodyfragments. Traditionally, these fragments were derived via proteolyticdigestion of intact antibodies (see, e.g., Morimoto et al., Journal ofBiochemical and Biophysical Methods 24: 107-117 (1992) and Brennan etal., Science, 229:81 (1985)). However, these fragments can now beproduced directly by recombinant host cells. For example, the antibodyfragments can be isolated from the antibody phage libraries discussedabove. Alternatively, Fab′-SH fragments can be directly recovered fromE. coli and chemically coupled to form F(ab′).sub.2 fragments (Carter etal., Bio/Technology 10: 163-167 (1992)). According to another approach,F(ab′).sub.2 fragments can be isolated directly from recombinant hostcell culture. Other techniques for the production of antibody fragmentswill be apparent to the skilled practitioner. Further, examples oftechniques which can be used to produce single-chain Fvs and antibodiesinclude those described in U.S. Pat. Nos. 4,946,778 and 5,258,498;Huston et al., Methods in Enzymology 203:46-88 (1991); Shu et al., PNAS90:7995-7999 (1993); and Skerra et al., Science 240:1038-1040 (1988).

The present invention encompasses antibodies recombinantly fused orchemically conjugated (including both covalently and non-covalentlyconjugations) to a polypeptide (or portion thereof, preferably at least10, 20 or 50 amino acids of the polypeptide) of the present invention togenerate fusion proteins. Thus, the invention also pertains toimmunoconjugates comprising the antibody described herein conjugated toa cytotoxic agent such as a chemotherapeutic agent, toxin (e.g. anenzymatically active toxin of bacterial, fungal, plant or animal origin,or fragments thereof), or a radioactive isotope (i.e., aradioconjugate).

The present invention encompasses antibodies recombinantly fused orchemically conjugated (including both covalently and non-covalentlyconjugations) to a polypeptide (or portion thereof, preferably at least10, 20 or 50 amino acids of the polypeptide) of the present invention togenerate fusion proteins. The fusion does not necessarily need to bedirect, but may occur through linker sequences. The antibodies may bespecific for antigens other than polypeptides (or portion thereof,preferably at least 10, 20 or 50 amino acids of the polypeptide) of thepresent invention. For example, antibodies may be used to target thepolypeptides of the present invention to particular cell types, eitherin vitro or in vivo, by fusing or conjugating the polypeptides of thepresent invention to antibodies specific for particular cell surfacereceptors. Antibodies fused or conjugated to the polypeptides of thepresent invention may also be used in in vitro immunoassays andpurification methods using methods known in the art. See e.g., Harbor etal., supra, and PCT publication WO 93/21232; EP 439,095; Naramura etal., Immunol. Lett. 39:91-99 (1994); U.S. Pat. No. 5,474,981; Gillies etal., PNAS 89:1428-1432 (1992); Fell et al., J. Immunol. 146:2446-2452(1991), which are incorporated by reference in their entireties.

The present invention further includes compositions comprising thepolypeptides of the present invention (e.g., those comprising animmunogenic or antigenic epitope) fused or conjugated to heterologouspolypeptide sequences (e.g., antibody domains other than the variableregions). For example, the polypeptides of the present invention may befused or conjugated to an antibody Fc region, or portion thereof. Forexample, polypeptides of the present invention (including fragments orvariants thereof), may be fused with the constant domain ofimmunoglobulins (IgA, IgE, IgG, IgM), or portions thereof (C_(H)1,C_(H2), C_(H3), or any combination thereof and portions thereof,resulting in chimeric polypeptides. The antibody portion fused to apolypeptide of the present invention may comprise the constant region,hinge region, C_(H1) domain, C_(H2) domain, and C_(H3) domain or anycombination of whole domains or portions thereof. The polypeptides mayalso be fused or conjugated to the above antibody portions to formmultimers. For example, Fc portions fused to the polypeptides of thepresent invention can form dimers through disulfide bonding between theFc portions. Higher multimeric forms can be made by fusing thepolypeptides to portions of IgA and IgM. Methods for fusing orconjugating the polypeptides of the present invention to antibodyportions are known in the art. See, e.g., U.S. Pat. Nos. 5,336,603;5,622,929; 5,359,046; 5,349,053; 5,447,851; 5,112,946; EP 307,434; EP367,166; PCT publications WO 96/04388; WO 91/06570; Ashkenazi et al.,Proc. Natl. Acad. Sci. USA 88:10535-10539 (1991); Zheng et al., J.Immunol. 154:5590-5600 (1995); and Vil et al., Proc. Natl. Acad. Sci.USA 89:11337-11341 (1992) (said references incorporated by reference intheir entireties). By way of another non-limiting example, polypeptidesand/or antibodies of the present invention (including fragments orvariants thereof) may be fused with albumin (including but not limitedto recombinant human serum albumin or fragments or variants thereof(see, e.g., U.S. Pat. No. 5,876,969, issued Mar. 2, 1999, EP Patent 0413 622, and U.S. Pat. No. 5,766,883, issued Jun. 16, 1998, hereinincorporated by reference in their entirety)). Polypeptides and/orantibodies of the present invention (including fragments or variantsthereof) may be fused to either the N- or C-terminal end of theheterologous protein (e.g., immunoglobulin Fc polypeptide or human serumalbumin polypeptide). Polynucleotides encoding fusion proteins of theinvention are also encompassed by the invention.

As discussed above, the polypeptides of the present invention may befused or conjugated to the above antibody portions to increase the invivo half life of the polypeptides or for use in immunoassays usingmethods known in the art. Further, the polypeptides of the presentinvention may be fused or conjugated to the above antibody portions tofacilitate purification. One reported example describes chimericproteins consisting of the first two domains of the humanCD4-polypeptide and various domains of the constant regions of the heavyor light chains of mammalian immunoglobulins. (See, e.g., EP 394,827;Traunecker et al., Nature 331:84-86 (1988)). Enhanced delivery of anantigen across the epithelial barrier to the immune system has beendemonstrated for antigens (e.g., insulin) conjugated to an FcRn bindingpartner such as IgG or Fc fragments (see, e.g., PCT Publications WO96/22024 and WO 99/04813). The polypeptides of the present inventionfused or conjugated to an antibody having disulfide-linked dimericstructures (due to the IgG) may also be more efficient in binding andneutralizing other molecules, than the monomeric secreted protein orprotein fragment alone. (Fountoulakis et al., J. Biochem. 270:3958-3964(1995)). In many cases, the Fc part in a fusion protein is beneficial intherapy and diagnosis, and thus can result in, for example, improvedpharmacokinetic properties. (EP A 232,262). Alternatively, deleting theFc part after the fusion protein has been expressed, detected, andpurified, would be desired. For example, the Fc portion may hindertherapy and diagnosis if the fusion protein is used as an antigen forimmunizations. In drug discovery, for example, human proteins, such ashIL-5, have been fused with Fc portions for the purpose ofhigh-throughput screening assays to identify antagonists of hIL-5. (See,D. Bennett et al., J. Molecular Recognition 8:52-58 (1995); K. Johansonet al., J. Biol. Chem. 270:9459-9471 (1995). Such techniques alsoinclude, but are not limited to, the use of bifunctional conjugatingagents (see e.g., U.S. Pat. Nos. 5,756,065; 5,714,631; 5,696,239;5,652,361; 5,505,931; 5,489,425; 5,435,990; 5,428,139; 5,342,604;5,274,119; 4,994,560; and 5,808,003; the contents of each of which arehereby incorporated by reference in its entirety).

Moreover, the polypeptides of the invention (e.g., antibodies orfragments thereof) can be fused to marker sequences, such as a peptideto facilitates their purification. In a further embodiment, nucleicacids encoding the polypeptides of the invention (including, but notlimited to nucleic acids encoding immunogenic and/or antigenic epitopes)can also be recombined with a gene of interest as an epitope tag (e.g.,the hemagglutinin tag (“HA”) or flag tag) to aid in detection andpurification of the expressed polypeptide. In preferred embodiments, themarker amino acid sequence is a hexa-histidine peptide, such as the tagprovided in a pQE vector (QIAGEN, Inc., 9259 Eton Avenue, Chatsworth,Calif., 91311), among others, many of which are commercially available.As described in Gentz et al., Proc. Natl. Acad. Sci. USA 86:821-824(1989), for instance, hexa-histidine provides for convenientpurification of the fusion protein. Other peptide tags useful forpurification include, but are not limited to, the “HA” tag, whichcorresponds to an epitope derived from the influenza hemagglutininprotein (Wilson et al., Cell 37:767 (1984)) and the “flag” tag.

The present invention further encompasses antibodies or fragmentsthereof conjugated to a diagnostic or therapeutic agent. The antibodiescan be used diagnostically to, for example, monitor the development orprogression of a tumor as part of a clinical testing procedure to, e.g.,determine the efficacy of a given treatment, diagnosis, detection,and/or prevention regimen. Detection can be facilitated by coupling theantibody to a detectable substance. Examples of detectable substancesinclude various enzymes, prosthetic groups, fluorescent materials,luminescent materials, bioluminescent materials, radioactive materials,positron emitting metals using various positron emission tomographies,and nonradioactive paramagnetic metal ions. See, for example, U.S. Pat.No. 4,741,900 for metal ions which can be conjugated to antibodies foruse as diagnostics according to the present invention. Examples ofsuitable enzymes include horseradish peroxidase, alkaline phosphatase,beta-galactosidase, or acetylcholinesterase; examples of suitableprosthetic group complexes include streptavidin/biotin andavidin/biotin; examples of suitable fluorescent materials includeumbelliferone, fluorescein, fluorescein isothiocyanate, rhodamine,dichlorotriazinylamine fluorescein, dansyl chloride or phycoerythrin; anexample of a luminescent material includes luminol; examples ofbioluminescent materials include luciferase, luciferin, and aequorin;and examples of suitable radioactive material include ¹²⁵I, ¹³¹I, ¹¹¹Inor ⁹⁹Tc.

Further, an antibody or fragment thereof may be conjugated to atherapeutic moiety such as a cytotoxin, e.g., a cytostatic or cytocidalagent, a therapeutic agent or a radioactive metal ion. A cytotoxin orcytotoxic agent includes any agent that is detrimental to cells.Examples include paclitaxol, cytochalasin B, gramicidin D, ethidiumbromide, emetine, mitomycin, etoposide, tenoposide, vincristine,vinblastine, colchicin, doxorubicin, daunorubicin, dihydroxy anthracindione, mitoxantrone, mithramycin, actinomycin D, 1-dehydrotestosterone,glucocorticoids, procaine, tetracaine, lidocaine, propranolol, andpuromycin and analogs or homologs thereof. Therapeutic agents include,but are not limited to, antimetabolites (e.g., methotrexate,6-mercaptopurine, 6-thioguanine, cytarabine, 5-fluorouracildecarbazine), alkylating agents (e.g., mechlorethamine, thioepachlorambucil, melphalan, carmustine (BSNU) and lomustine (CCNU),cyclothosphamide, busulfan, dibromomannitol, streptozotocin, mitomycinC, and cis-dichlorodiamine platinum (II) (DDP) cisplatin),anthracyclines (e.g., daunorubicin (formerly daunomycin) anddoxorubicin), antibiotics (e.g., dactinomycin (formerly actinomycin),bleomycin, mithramycin, and anthramycin (AMC)), and anti-mitotic agents(e.g., vincristine and vinblastine).

The conjugates of the invention can be used for modifying a givenbiological response, the therapeutic agent or drug moiety is not to beconstrued as limited to classical chemical therapeutic agents. Forexample, the drug moiety may be a protein or polypeptide possessing adesired biological activity. Such proteins may include, for example, atoxin such as abrin, ricin A, pseudomonas exotoxin, or diphtheria toxin;a protein such as tumor necrosis factor, a-interferon,.beta.-interferon, nerve growth factor, platelet derived growth factor,tissue plasminogen activator, a thrombotic agent or an anti-angiogenicagent, e.g., angiostatin or endostatin; or, biological responsemodifiers such as, for example, lymphokines, interleukin-1 (“IL-1”),interleukin-2 (“IL-2”), interleukin-6 (“IL-6”), granulocyte macrophasecolony stimulating factor (“GM-CSF”), granulocyte colony stimulatingfactor (“G-CSF”), or other growth factors.

Antibodies may also be attached to solid supports, which areparticularly useful for immunoassays or purification of the targetantigen. Such solid supports include, but are not limited to, glass,cellulose, polyacrylamide, nylon, polystyrene, polyvinyl chloride orpolypropylene.

Techniques for conjugating such therapeutic moiety to antibodies arewell known, see, e.g., Arnon et al., “Monoclonal Antibodies ForImmunotargeting Of Drugs In Cancer Therapy”, in Monoclonal AntibodiesAnd Cancer Therapy, Reisfeld et al. (eds.), pp. 243-56 (Alan R. Liss,Inc. 1985); Hellstrom et al., “Antibodies For Drug Delivery”, inControlled Drug Delivery (2nd Ed.), Robinson et al. (eds.), pp. 623-53(Marcel Dekker, Inc. 1987); Thorpe, “Antibody Carriers Of CytotoxicAgents In Cancer Therapy: A Review”, in Monoclonal Antibodies '84:Biological And Clinical Applications, Pinchera et al. (eds.), pp.475-506 (1985); “Analysis, Results, And Future Prospective Of TheTherapeutic Use Of Radiolabeled Antibody In Cancer Therapy”, inMonoclonal Antibodies For Cancer Detection And Therapy, Baldwin et al.(eds.), pp. 303-16 (Academic Press 1985), and Thorpe et al., “ThePreparation And Cytotoxic Properties Of Antibody-Toxin Conjugates”,Immunol. Rev. 62:119-58 (1982).

Alternatively, an antibody can be conjugated to a second antibody toform an antibody heteroconjugate as described by Segal in U.S. Pat. No.4,676,980, which is incorporated herein by reference in its entirety.

An antibody, with or without a therapeutic moiety conjugated to it,administered alone or in combination with cytotoxic factor(s) and/orcytokine(s) can be used as a therapeutic.

In another embodiment, the antibody may be conjugated to a “receptor”(such streptavidin) for utilization in tumor pretargeting wherein theantibody-receptor conjugate is administered to the patient, followed byremoval of unbound conjugate from the circulation using a clearing agentand then administration of a “ligand” (e.g. avidin) which is conjugatedto a cytotoxic agent (e.g. a radionuclide).

A variety of assays known to those skilled in the art can be utilized todetect antibodies which bind to IL-31 proteins or polypeptides.Exemplary assays are described in detail in Antibodies: A LaboratoryManual, Harlow and Lane (Eds.), Cold Spring Harbor Laboratory Press,1988. Representative examples of such assays include: concurrentimmunoelectrophoresis, radioimmunoassay, radioimmuno-precipitation,enzyme-linked immunosorbent assay (ELISA), dot blot or Western blotassay, inhibition or competition assay, and sandwich assay. In addition,antibodies can be screened for binding to wild-type versus mutant IL-31protein or polypeptide.

Antibodies to IL-31 may be used for tagging cells that express IL-31;for isolating IL-31 by affinity purification; for diagnostic assays fordetermining circulating levels of IL-31 polypeptides; for detecting orquantitating soluble IL-31 as a marker of underlying pathology ordisease; in analytical methods employing FACS; for screening expressionlibraries; for generating anti-idiotypic antibodies; and as neutralizingantibodies or as antagonists to block IL-31 activity in vitro and invivo. Suitable direct tags or labels include radionuclides, enzymes,substrates, cofactors, inhibitors, fluorescent markers, chemiluminescentmarkers, magnetic particles and the like; indirect tags or labels mayfeature use of biotin-avidin or other complement/anti-complement pairsas intermediates. Antibodies herein may also be directly or indirectlyconjugated to drugs, toxins, radionuclides and the like, and theseconjugates used for in vivo diagnostic or therapeutic applications.Moreover, antibodies to IL-31 or fragments thereof may be used in vitroto detect denatured IL-31 or fragments thereof in assays, for example,Western Blots or other assays known in the art.

Suitable detectable molecules may be directly or indirectly attached tothe polypeptide or antibody, and include radionuclides, enzymes,substrates, cofactors, inhibitors, fluorescent markers, chemiluminescentmarkers, magnetic particles and the like. Suitable cytotoxic moleculesmay be directly or indirectly attached to the polypeptide or antibody,and include bacterial or plant toxins (for instance, diphtheria, toxin,saporin, Pseudomonas exotoxin, ricin, abrin and the like), as well astherapeutic radionuclides, such as iodine-131, rhenium-188 or yttrium-90(either directly attached to the polypeptide or antibody, or indirectlyattached through means of a chelating moiety, for instance).Polypeptides or antibodies may also be conjugated to cytotoxic drugs,such as adriamycin. For indirect attachment of a detectable or cytotoxicmolecule, the detectable or cytotoxic molecule can be conjugated with amember of a complementary/anticomplementary pair, where the other memberis bound to the polypeptide or antibody portion. For these purposes,biotin/streptavidin is an exemplary complementary/anticomplementarypair.

Binding polypeptides can also act as IL-31 “antagonists” to block IL-31binding and signal transduction in vitro and in vivo. These anti-IL-31binding polypeptides would be useful for inhibiting IL-31 activity orprotein-binding.

Polypeptide-toxin fusion proteins or antibody-toxin fusion proteins canbe used for targeted cell or tissue inhibition or ablation (forinstance, to treat cancer cells or tissues). Alternatively, if thepolypeptide has multiple functional domains (i.e., an activation domainor a receptor binding domain, plus a targeting domain), a fusion proteinincluding only the targeting domain may be suitable for directing adetectable molecule, a cytotoxic molecule or a complementary molecule toa cell or tissue type of interest. In instances where the domain onlyfusion protein includes a complementary molecule, the anti-complementarymolecule can be conjugated to a detectable or cytotoxic molecule. Suchdomain-complementary molecule fusion proteins thus represent a generictargeting carrier or vehicle for cell/tissue-specific delivery ofgeneric anti-complementary-detectable/cytotoxic molecule conjugates.

In another embodiment, IL-31 antibody-cytokine fusion proteins can beused for in vivo killing of target tissues (for example, leukemia,lymphoma, lung cancer, colon cancer, melanoma, pancreatic cancer,ovarian cancer, skin, blood and bone marrow cancers, or other cancerswherein IL-31 receptors ar expressed) (See, generally, Hornick et al.,Blood 89:4437-47, 1997). The described fusion proteins enable targetingof the antibody to a desired site of action, thereby providing anelevated local concentration of antibody. Suitable IL-31 polypeptides oranti-IL-31 antibodies target an undesirable cell or tissue (i.e., atumor or a leukemia), and the fused cytokine mediated improved targetcell lysis by effector cells. Suitable cytokines for this purposeinclude interleukin 2 and granulocyte-macrophage colony-stimulatingfactor (GM-CSF), for instance.

In yet another embodiment, if the IL-31 polypeptide or anti-IL-31antibody targets vascular cells or tissues, such polypeptide or antibodymay be conjugated with a radionuclide, and particularly with abeta-emitting radionuclide, to reduce restenosis.

The monoclonal antibodies of the present invention can be measured fortheir ability to inhibit, block, or neutralize the IL-31 ligand asdetermined by various in vivo models known in the art and describedherein, including but not limited to the NC/Nga model, the Ovaepicutaneous model, the chronic hypersensitivity model, and the chronichapten model.

Both skin-homing T cells and epidermal keratinocytes have beenimplicated in the pathology of skin diseases in humans. IL-31 mRNA andprotein expression is restricted to the skin-homing CLA+ T cellpopulation in humans. As such, an antagonist to IL-31, including anantibody or receptor antagonist will be useful in treating skin andepidermal diseases which have expression of CLA+ T cells. Such diseasesinclude, for example, atopic dermatitis, contact dermatitis,drug-induced allergic reactions, skin-tropic viruses and viralassociated pruritis, vitiligo, cutaneous T cell lymphoma, alopeciaaerata, acne rosacea, acne vulgaris, prurigo nodularis, and bullouspemphigoid. Chemokine markers such as TARC and MDC are useful to measurethe effect of a neutralizing monoclonal antibody to IL-31. As shown inExample 15, the inhibitory effects of treatment with anti-Il31antibodies described herein can be measured by monitoring the levels ofTARC and MDC.

Contact Dermatitis

Allergic contact dermatitis is defined as a T cell mediated immunereaction to an antigen that comes into contact with the skin. The CLA+ Tcell population is considered to be involved in the initiation ofdermatitis since allergen dependent T cell responses are largelyconfined to the CLA+ population of cells (See Santamaria-Babi, L. F., etal., J Exp Med: 181, 1935, (1995)). Recent data has found that onlymemory (CD45RO+) CD4+ CLA+ and not CD8+ T cells proliferate and produceboth type-1 (IFN-) and type-2 (IL-5) cytokines in response to nickel, acommon contact hypersensitivity allergen. Furthermore, cells expressingCLA in combination with CD4, CD45RO (memory) or CD69 are increased afternickel-specific stimulation and express the chemokine receptors CXCR3,CCR4, CCR10 but not CCR6. See Moed H., et al., Br J Dermatol: 51, 32,(2004).

In animal models, it has been demonstrated that allergic contactdermatitis is T-cell dependent and that the allergic-responsive T cellsmigrate to the site of allergen application. See generally: Engeman T.M., et al., J Immunol: 164, 5207, (2000); Ferguson T. A. & Kupper T. S.J Immunol: 150, 1172, (1993); and Gorbachev A. V. & Fairchild R. L. CritRev Immunol: 21, 451 (2001). Since CLA+ T cells produce IL-31 and IL-31stimulation of skin keratinocytes can induce pro-inflammatorychemokines, such as TARC and MDC, IL-31 may be involved in thepathophysiology of contact dermatitis. By using a neutralizing IL-31antibody in a mouse model of contact hypersensitivity. See Example 8.

Thus, neutralization of IL-31 by the antibodies described herein may beused to improve clinical outcome of Contat Hypersenstivity byinhibition, reduction, neutralization, prevention or blocking theinflammation and/or scratching associated with disease.

Atopic Dermatitis

Atopic dermatitis (AD) is a chronically relapsing inflammatory skindisease with a dramatically increasing incidence over the last decades.Clinically AD is characterized by highly pruritic often excoriatedplaques and papules that show a chronic relapsing course. The diagnosisof AD is mostly based on major and minor clinical findings. See HanifinJ. M., Arch Dermatol: 135, 1551 (1999). Histopathology revealsspongiosis, hyper and focal parakeratosis in acute lesions, whereasmarked epidermal hyperplasia with hyper and parakeratosis,acanthosis/hypergranulosis and perivascular infiltration of the dermiswith lymphocytes and abundant mast cells are the hallmarks of chromiclesions.

T cells play a central role in the initiation of local immune responsesin tissues and evidence suggests that skin-infiltrating T cells inparticular, may play a key role in the initiation and maintenance ofdisregulated immune responses in the skin. Approximately 90% ofinfiltrating T cells in cutaneous inflammatory sites express thecutaneous lymphocyte-associated Ag (CLA+) which binds E-selectin, aninducible adhesion molecule on endothelium (reviewed in Santamaria-BabiL. F., et al., Eur J Dermatol: 14, 13, (2004)). A significant increasein circulating CLA+ T cells among AD patients compared with controlindividuals has been documented (See Teraki Y., et al., Br J Dermatol:143, 373 (2000), while others have demonstrated that memory CLA+ T cellsfrom AD patients preferentially respond to allergen extract compared tothe CLA− population (See Santamaria-Babi, L. F., et al., J Exp Med: 181,1935, (1995)). In humans, the pathogenesis of atopic disorders of theskin have been associated with increases in CLA+ T cells that expressincreased levels of Th-2-type cytokines like IL-5 and IL-13 9, 10. SeeAkdis M., et al., Eur J Immunol: 30, 3533 (2000); and Hamid Q., et al.,J Allergy Clin Immunol: 98, 225 (1996).

NC/Nga Mice spontaneously develop AD-like lesions that parallel human ADin many aspects, including clinical course and signs, histophathologyand immunopathology when housed in non-specified pathogen-free (non-SPF)conditions at around 6-8 weeks of age. In contrast, NC/Nga mice keptunder SPF conditions do not develop skin lesions. However, onset ofspontaneous skin lesions and scratching behaviour can be synchronized inNC/Nga mice housed in a SPF facility by weekly intradermal injection ofcrude dust mite antigen. See Matsuoka H., et al., Allergy: 58, 139(2003). Therefore, the development of AD in NC/Nga is a useful model forthe evaluation of novel therapeutics for the treatment of AD.

In addition to the NC/Nga model of spontaneous AD, epicutaneoussensitization of mice using OVA can also be used as a model to induceantigen-dependent epidermal and dermal thickening with a mononuclearinfiltrate in skin of sensitized mice. This usually coincides withelevated serum levels of total and specific IgE, however no skin barrierdysfunction or pruritus normally occurs in this model. See Spergel J.M., et al., J Clin Invest, 101: 1614, (1998). This protocol can bemodified in order to induce skin barrier disregulation and pruritis bysensitizing DO11.10 OVA TCR transgenic mice with OVA. Increasing thenumber of antigen-specific T cells that could recognize the sensitizingantigen may increase the level of inflammation in the skin to inducevisible scratching behaviour and lichenification/scaling of the skin.

Both the NC/Nga spontaneous AD model and the OVA epicutaneous DO11.10model are used to investigate expression of IL-31 and IL-31RA in AD, aswell as the ability of the antibodies described herein to inhibit,reduce, or neutralize the effects of IL-31. See Examples 9 and 10herein. In one study using the NC/Nga in vivo model (Example 10),administration of rat anti-mouse IL-31 antibodies showed reduction inscratching, but not a reduction in dermatitis. The antibodies describedherein are useful to inhibit scratching associated with dermatitis andpruritic diseases including atopic dermatitis, prurigo nodularis, andeczema. An inhibition, reduction, or prevention of scratching, alone,can be effective in treating pruritic diseases including, but notlimited to, atopic dermatitis, prurigo nodularis, and eczema, sincecessation of scratching will stop progression of dermatitis, thedevelopment of which is dependent on scratching.

Additional models to measure the inhibitory effects of the anti-IL-31antibodies described herein are described by Umeuchi, H. et al.,European Journal of Pharmacology, 518: 133-139, 2005; and by Yoo, J. etal., J. Experimental Medicine, 202:541-549, 2005.

Thus, neutralization of IL-31 by the antibodies described herein may beused to improve clinical outcome of dermatitis and pruritic diseasesincluding atopic dermatitis, prurigo nodularis, and eczema byinhibition, reduction, prevention or blocking the inflammation and/orscratching associated with disease.

Drug-Induced Delayed Type Cutaneous Allergic Reactions

Drug-induced delayed type cutaneous allergic reactions are veryheterogeneous and may mirror many distinct pathophysiological events.See Brockow K., et al., Allergy: 57, 45 (2002). Immunological mechanismsinvolved in these reactions have been shown as either antibody or cellmediated. In immediate drug allergy an IgE-mediated antibody reactioncan be demonstrated by a positive skin prick and/or intradermal testafter 20 min, whereas non-immediate reactions to drugs can occur morethan one hour after last drug intake and are often T-cell mediated.Non-immediate T-cell mediated delayed type reactions can occur inpatients with adverse drug reactions to penicillins for example.Proliferative T cell responses to penicillins have been shown to berestricted to the memory (CD45RO+) CLA+ subpopulation of T cells frompenicillin allergic patients whereas the CD45RO+ CLA− subset shows noproliferative response. See Blanca M., Leyva L., et al., Blood Cells MolDis: 31, 75 (2003). Delayed-type hypersensitivity (DTH) reactions can beartificially reproduced in mice, allowing assessment of factors that maybe involved in the initiation and perpetuation of the DTH response.Il-31 neutralizing antibody could be effective in delayed typehypersensitivity reactions. See Example 51.

Toxic epidermal necrolysis (TEN) is a very rare but extremely severedrug reaction characterized by widespread apoptosis of epidermis withextensive blisters. Studies have shown that lymphocytes infiltrating theblister are CLA+ T cells and can exhibit cytotoxicity towards epidermalkeratinocytes. See Leyva L., et al., J Allergy Clin Immunol: 105, 157(2000); and Nassif A., Bensussan A., et al., J Allergy Clin Immunol:114, 1209 2004). A transgenic mouse system, whereby OVA is expressedunder the control of the keratin-5 (K5) promoter in the epidermal andhair follicular keratinocytes of mice, has been generated to establishan animal model for TEN. OVA specific CD8+ T cells, when adoptivelytransferred into K5-OVA mice, undergo activation and proliferation inthe skin-draining lymph nodes and target the skin of K5-OVA mice,resulting in development of skin lesions that are reminiscent of TEN.See Azukizawa H., et al., Eur J Immunol: 33, 1879 (2003).

Thus, neutralization of IL-31 by the antibodies described herein may beused to improve clinical outcome of TEN by inhibition, reduction,prevention or blocking the inflammation and/or scratching associatedwith disease.

Bullous Pemphigoid

Bullous pemphigoid is a subepidermal disorder which manifests assubepidermal blisters with a dermal infiltrate of neutrophils andeosinophils. Diagnosis is characterized by the presence ofantigen-specific antibodies against specific adhesion proteins of theepidermis and dermal-epidermal junction. See Jordon R. E., et al., JAMA:200, 751 (1967). Studies analyzing the role of T cells in thepathogenesis of bullous pemphigoid by analysis of PBL and skin blister Tcells have found a predominance of CLA+ T cells expressing increasedlevels of Th2-cytokines like IL-4 and IL-13. See Teraki Y., et al., JInvest Dermatol: 117, 1097 (2001). In bullous pemphigoid patientsfollowing therapy with systemic corticosteroids, the frequency of CLA+,but not CLA−, interleukin-13-producing cells is significantly decreased.Decreases in CLA+ cells following corticosteroid treatment is associatedwith clinical improvement. See Teraki, ibid.

Thus, neutralization of IL-31 by the antibodies described herein may beused to improve clinical outcome of bullous pemphigoid by inhibition,reduction, prevention or blocking the inflammation and/or scratchingassociated with disease.

Alopecia Areata

Alopecia areata (AA) is regarded as a tissue-restricted autoimmunedisease of hair follicles in which follicular activity is arrestedbecause of the continued activity of lymphocytic infiltrates. AA resultsin patches of complete hair loss anywhere on the body, though actualloss of hair follicles does not occur, even in hairless lesions.Although clinical signs of inflammation are absent, skin biopsies fromsites of active disease show perifollicular lymphocytic inflammation ofprimarily CD4+ cells, along with a CD8+ intrafollicular infiltrate. SeeKalish R. S. & Gilhar A. J Investig Dermatol Symp Proc: 8, 164 (2003).

Studies have shown that scalp skin infiltrating CD4+ or CD8+ lymphocytesexpress CLA and, in peripheral blood of individuals with AA, the percentof CLA+ CD4+ or CD8+ lymphocytes is significantly higher than that ofnormal controls. Furthermore, patients with severe or progressive AAshow a much higher CLA-positivity compared to patients recovering fromthe disease and a decrease in percent CLA+ cells parallels a goodclinical course. See Yano S., et al., Acta Derm Venereol: 82, 82 (2002).These studies therefore suggest that CLA+ lymphocytes may play animportant role in AA. Xenograft models have demonstrated that activatedT cells are likely to play a role in the pathogenesis of AA. Lesionalscalp from AA patients grafted onto nude mice regrows hair coincidentwith a loss of infiltrating lymphocytes from the graft and, transfer ofactivated lesional T cells to SCID mice can transfer hair loss to humanscalp explants on SCID mice. See Kalish R. S. & Gilhar A. J InvestigDermatol Symp Proc: 8, 164 (2003).

A variety of immunomodulating therapies are part of the usual treatmentfor this disorder however none of these treatments have been consistentin their efficacy. See Tang L., et al., J Invest Dermatol: 120, 400(2003); Tang L., et al., (2004); and Tang L., et al., J Am AcadDermatol: 49, 1013 (2003). Nevertheless, their uses in valid animalmodels provide a tool to dissect out molecular mechanisms of therapeuticeffects. See Shapiro J., et al., J Investig Dermatol Symp Proc: 4, 239(1999); Tang L., et al., Old wine in new bottles: reviving old therapiesfor alopecia areata using rodent models (2003); and Verma D. D., et al.,Eur J Dermatol: 14, 332 (2004).

Thus, neutralization of IL-31 by the antibodies described herein may beused to improve clinical outcome of alopecia areata by inhibition,reduction, prevention or blocking the inflammation and/or scratchingassociated with disease.

Acne Rosacea/Acne Vulgaris

Acne vulgaris, a disorder of the pilosebaceous apparatus, is the mostcommon skin problem of adolescence. Abnormalities in follicularkeratinization are thought to produce the acne lesion. Acne rosacea isdifferentiated from acne vulagaris by the presence of red papules,pustules, cysts and extensive telangiectasias, but the absence ofcomedones (white heads). Increased sebum excretion from sebaceous glandsis a major factor in the pathophysiology of acne vulgaris. Othersebaceous gland functions are also associated with the development ofacne, including sebaceous proinflammatory lipids; different cytokinesproduced locally; periglandular peptides and neuropeptides, such ascorticotrophin-releasing hormone, which is produced by sebocytes; andsubstance P, which is expressed in the nerve endings at the vicinity ofhealthy-looking glands of acne patients. See Zouboulis C. C. ClinDermatol: 22, 360 (2004).

Although the pathophysiology of acne vulgaris and acne rosacea remainsunknown, clinical observations and histopathologic studies suggest thatinflammation of the pilosebaceous follicle may be central to thepathogenesis of rosacea and acne vulgaris. Early studies on analysis ofT cell subsets infiltrating rosacea legions indicated that the majorityof T cells expressed CD4. See Rufli T. & Buchner S. A. Dermatologica:169, 1 (1984).

CD4+ T cells produce IL-31 and IHC analysis of skin for IL-31 expressionsuggests that IL-31 is expressed in sebaceous and sweat glands. IL-31stimulation of epidermal keratinocytes induces expression of chemokineswhich likely results in cellular infiltration suggesting that IL-31 maycontribute to the pro-inflammatory response in skin. See Dillon S. R.,et al., Nat Immunol: 5, 752 (2004). IL-31 may therefore contribute tothe pathophysiology of acne rosacea and acne vulgaris.

Thus, neutralization of IL-31 by the antibodies described herein may beused to improve clinical outcome of acne vulgaris by inhibition,reduction, prevention or blocking the inflammation and/or scratchingassociated with disease.

Prurigo Nodularis

Prurigo nodularis is an eruption of lichenified or excoriated nodulescaused by intractable pruritus that is difficult to treat. While chronicrubbing results in lichenification, and scratching in linearexcoriations, individuals who pick and gouge at their itchy, irritatedskin tend to produce markedly thickened papules known as prurigonodules. Although prurigo nodularis is not specific to atopicdermatitis, many patients with these nodules also have an atopicreaction, which manifests as allergic rhinitis, asthma, or food allergy.T cells represent the majority of infiltrating cells in prurigo lesionsand these lesions often represents the most pruritic skin lesion inatopy patients.

Topical treatment of prurigo nodularis with capsaicin, an anti-pruriticalkaloid that interferes with the perception of prurities and pain bydepletion of neuropeptides like substance P in small sensory cutaneousnerves, has proven to be an effective and safe regimen resulting inclearing of the skin lesions. See Stander S., et al., J Am AcadDermatol: 44, 471 (2001). Studies of the itch response in NC/Nga miceusing capsaicin treatment showed that the spontaneous development ofdermatitis lesions was almost completely prevented. Furthermore, theelevation of serum IgE levels was significantly suppressed andinfiltrating eosinophils and mast cell numbers in lesional skin ofcapsaicin treated mice were reduced. See Mihara K., et al., Br JDermatol: 151, 335 (2004). The observations from this group suggest thatscratching behaviour might contribute to the development of dermatitisby enhancing various immunological responses, therefore implying thatprevention of the itch sensation and/or itch-associated scratchingbehaviour might be an effective treatment for AD. See Mihara K., et al.,Br J Dermatol: 151, 335 (2004). Thus, the anti-Il-31 antibodiesdescribed herein will be useful in minimizing the effects of AD, prurigonodularis, and other pruritic diseases as they are shown herein toreduce the amount of scratching in NC/Nga mice.

Chronic delivery of IL-31 induces pruritis and alopecia in mice followedby the development of skin lesions resembling dermatitis suggesting thatIL-31 may induce itching. See Dillon S. R., et al., Nat Immunol: 5, 752(2004). The involvement of IL-31 was tested in induction of the itchresponse by two methods (i) capsaicin treatment of IL-31-treated miceand (ii) IL-31 treatment of Tac1 knockout mice, which have significantlyreduced nociceptive pain responses because of lack of expression ofneuropeptides in Example 52. In addition, whether neutralization ofIL-31 in IL-31 treated mice could prevent pruritis and alopecia wastested in Example 12.

Thus, neutralization of IL-31 by the antibodies described herein may beused to improve clinical outcome of prurigo nodularis by inhibition,reduction, prevention or blocking the inflammation and/or scratchingassociated with disease.

Skin-Tropic Viruses and Viral Associated Pruritis

Herpes Simplex Virus (HSV)-specific CD8+ T cells in the peripheral bloodand HSV-specific CD8+ T cells recovered from herpes lesions express highlevels of CLA where as non-skin-tropic herpes virus-specific CD8+ Tcells lack CLA expression. See Koelle D. M., et al., J Clin Invest: 110,537 (2002). HSV-2 reactive CD4+ T lymphocytes also express CLA, but atlevels lower than those previously observed for CD8+ T lymphocytes. SeeGonzalez J. C., et al., J Infect Dis: 191, 243 (2005). Pruritis has alsobeen associated with herpes viral infections (See Hung K. Y., et al.,Blood Purif: 16, 147 (1998), though other viral diseases, like HIV, havealso been associated with pruritic skin lesions. Severe, intractablepruritus, often associated with erythematopapular skin lesions andhypereosinophilia, is a condition observed in some nonatopic,HIV-infected patients 36. See Singh F. & Rudikoff D, Am J Clin Dermatol;4, 177 (2003); and Milazzo F., Piconi S., et al., Allergy: 54, 266(1999).

The association of skin-tropic viruses with pruritis and CLA+ T cellssuggests that IL-31 producing T cells may be involved in thepathophysiology of viral infections.

Thus, neutralization of IL-31 by the antibodies described herein may beused to improve clinical outcome of pruritis associated with skin-tropicviruses by inhibition, reduction, prevention or blocking theinflammation and/or scratching associated with disease.

Moreover, inflammation is a protective response by an organism to fendoff an invading agent. Inflammation is a cascading event that involvesmany cellular and humoral mediators. On one hand, suppression ofinflammatory responses can leave a host immunocompromised; however, ifleft unchecked, inflammation can lead to serious complications includingchronic inflammatory diseases (e.g., rheumatoid arthritis, multiplesclerosis, inflammatory bowel disease and the like), septic shock andmultiple organ failure. Importantly, these diverse disease states sharecommon inflammatory mediators. The collective diseases that arecharacterized by inflammation have a large impact on human morbidity andmortality. Therefore it is clear that anti-inflammatory antibodies andbinding polypeptides, such as anti-IL-31 antibodies and bindingpolypeptides described herein, could have crucial therapeutic potentialfor a vast number of human and animal diseases, from asthma and allergyto autoimmunity and septic shock. As such, use of anti-inflammatory antiIL-31 antibodies and binding polypeptides described herein can be usedtherapeutically as IL-31 antagonists described herein, particularly indiseases such as arthritis, endotoxemia, inflammatory bowel disease,psoriasis, related disease and the like.

1. Arthritis

Arthritis, including osteoarthritis, rheumatoid arthritis, arthriticjoints as a result of injury, and the like, are common inflammatoryconditions which would benefit from the therapeutic use ofanti-inflammatory antibodies and binding polypeptides, such asanti-IL-31 antibodies and binding polypeptides of the present invention.For Example, rheumatoid arthritis (RA) is a systemic disease thataffects the entire body and is one of the most common forms ofarthritis. It is characterized by the inflammation of the membranelining the joint, which causes pain, stiffness, warmth, redness andswelling. Inflammatory cells release enzymes that may digest bone andcartilage. As a result of rheumatoid arthritis, the inflamed jointlining, the synovium, can invade and damage bone and cartilage leadingto joint deterioration and severe pain amongst other physiologiceffects. The involved joint can lose its shape and alignment, resultingin pain and loss of movement.

Rheumatoid arthritis (RA) is an immune-mediated disease particularlycharacterized by inflammation and subsequent tissue damage leading tosevere disability and increased mortality. A variety of cytokines areproduced locally in the rheumatoid joints. Numerous studies havedemonstrated that IL-1 and TNF-alpha, two prototypic pro-inflammatorycytokines, play an important role in the mechanisms involved in synovialinflammation and in progressive joint destruction. Indeed, theadministration of TNF-alpha and IL-1 inhibitors in patients with RA hasled to a dramatic improvement of clinical and biological signs ofinflammation and a reduction of radiological signs of bone erosion andcartilage destruction. However, despite these encouraging results, asignificant percentage of patients do not respond to these agents,suggesting that other mediators are also involved in the pathophysiologyof arthritis (Gabay, Expert. Opin. Biol. Ther. 2(2):135-149, 2002). Oneof those mediators could be IL-31, and as such a molecule that binds orinhibits IL-31, such as anti IL-31 antibodies or binding partners, couldserve as a valuable therapeutic to reduce inflammation in rheumatoidarthritis, and other arthritic diseases.

There are several animal models for rheumatoid arthritis known in theart. For example, in the collagen-induced arthritis (CIA) model, micedevelop chronic inflammatory arthritis that closely resembles humanrheumatoid arthritis. Since CIA shares similar immunological andpathological features with RA, this makes it an ideal model forscreening potential human anti-inflammatory compounds. The CIA model isa well-known model in mice that depends on both an immune response, andan inflammatory response, in order to occur. The immune responsecomprises the interaction of B-cells and CD4+ T-cells in response tocollagen, which is given as antigen, and leads to the production ofanti-collagen antibodies. The inflammatory phase is the result of tissueresponses from mediators of inflammation, as a consequence of some ofthese antibodies cross-reacting to the mouse's native collagen andactivating the complement cascade. An advantage in using the CIA modelis that the basic mechanisms of pathogenesis are known. The relevantT-cell and B-cell epitopes on type II collagen have been identified, andvarious immunological (e.g., delayed-type hypersensitivity andanti-collagen antibody) and inflammatory (e.g., cytokines, chemokines,and matrix-degrading enzymes) parameters relating to immune-mediatedarthritis have been determined, and can thus be used to assess testcompound efficacy in the CIA model (Wooley, Curr. Opin. Rheum. 3:407-20,1999; Williams et al., Immunol. 89:9784-788, 1992; Myers et al., LifeSci. 61:1861-78, 1997; and Wang et al., Immunol. 92:8955-959, 1995).

The administration of soluble IL-31RA comprising polypeptides (includingheterodimeric and multimeric receptors described herein), such asIL-31RA-Fc4 or other IL-31RA soluble and fusion proteins to these CIAmodel mice was used to evaluate the use of TL-31RA to amelioratesymptoms and alter the course of disease. As a molecule that modulatesimmune and inflammatory response, IL-31, may induce production of SAA,which is implicated in the pathogenesis of rheumatoid arthritis, IL-31antagonists may reduce SAA activity in vitro and in vivo, the systemicor local administration of IL-31 antagonists such as anti-IL-31antibodies or binding partners, IL-31RA comprising polypeptides(including heterodimeric and multimeric receptors described herein),such as IL-31RA-Fc4 or other IL-31RA soluble and fusion proteins canpotentially suppress the inflammatory response in RA. Other potentialtherapeutics include IL-31RA polypeptides, soluble heterodimeric andmultimeric receptor polypeptides, or anti IL-31 antibodies or bindingpartners of the present invention, and the like.

2. Endotoxemia

Endotoxemia is a severe condition commonly resulting from infectiousagents such as bacteria and other infectious disease agents, sepsis,toxic shock syndrome, or in immunocompromised patients subjected toopportunistic infections, and the like. Therapeutically useful ofanti-inflammatory antibodies and binding polypeptides, such asanti-IL-31 antibodies and binding polypeptides of the present invention,could aid in preventing and treating endotoxemia in humans and animals.Other potential therapeutics include IL-31RA polypeptides, solubleheterodimeric and multimeric receptor polypeptides, or anti IL-31antibodies or binding partners of the present invention, and the like,could serve as a valuable therapeutic to reduce inflammation andpathological effects in endotoxemia.

Lipopolysaccharide (LPS) induced endotoxemia engages many of theproinflammatory mediators that produce pathological effects in theinfectious diseases and LPS induced endotoxemia in rodents is a widelyused and acceptable model for studying the pharmacological effects ofpotential pro-inflammatory or immunomodulating agents. LPS, produced ingram-negative bacteria, is a major causative agent in the pathogenesisof septic shock (Glausner et al., Lancet 338:732, 1991). A shock-likestate can indeed be induced experimentally by a single injection of LPSinto animals. Molecules produced by cells responding to LPS can targetpathogens directly or indirectly. Although these biological responsesprotect the host against invading pathogens, they may also cause harm.Thus, massive stimulation of innate immunity, occurring as a result ofsevere Gram-negative bacterial infection, leads to excess production ofcytokines and other molecules, and the development of a fatal syndrome,septic shock syndrome, which is characterized by fever, hypotension,disseminated intravascular coagulation, and multiple organ failure(Dumitru et al. Cell 103:1071-1083, 2000).

These toxic effects of LPS are mostly related to macrophage activationleading to the release of multiple inflammatory mediators. Among thesemediators, TNF appears to play a crucial role, as indicated by theprevention of LPS toxicity by the administration of neutralizinganti-TNF antibodies (Beutler et al., Science 229:869, 1985). It is wellestablished that 1 ug injection of E. coli LPS into a C57Bl/6 mouse willresult in significant increases in circulating IL-6, TNF-alpha, IL-1,and acute phase proteins (for example, SAA) approximately 2 hours postinjection. The toxicity of LPS appears to be mediated by these cytokinesas passive immunization against these mediators can result in decreasedmortality (Beutler et al., Science 229:869, 1985). The potentialimmunointervention strategies for the prevention and/or treatment ofseptic shock include anti-TNF mAb, IL-1 receptor antagonist, LIF, IL-10,and G-CSF. Since LPS induces the production of pro-inflammatory factorspossibly contributing to the pathology of endotoxemia, theneutralization of IL-31 activity, SAA or other pro-inflammatory factorsby antagonizing IL-31 polypeptide can be used to reduce the symptoms ofendotoxemia, such as seen in endotoxic shock. Other potentialtherapeutics include IL-31RA polypeptides, soluble heterodimeric andmultimeric receptor polypeptides, or anti-IL-31 antibodies or bindingpartners of the present invention, and the like.

3 Inflammatory Bowel Disease. IBD

In the United States approximately 500,000 people suffer fromInflammatory Bowel Disease (IBD) which can affect either colon andrectum (Ulcerative colitis) or both, small and large intestine (Crohn'sDisease). The pathogenesis of these diseases is unclear, but theyinvolve chronic inflammation of the affected tissues. Potentialtherapeutics include IL-31RA polypeptides, soluble heterodimeric andmultimeric receptor polypeptides, or anti-IL-31 antibodies or bindingpartners of the present invention, and the like, could serve as avaluable therapeutic to reduce inflammation and pathological effects inIBD and related diseases.

Ulcerative colitis (UC) is an inflammatory disease of the largeintestine, commonly called the colon, characterized by inflammation andulceration of the mucosa or innermost lining of the colon. Thisinflammation causes the colon to empty frequently, resulting indiarrhea. Symptoms include loosening of the stool and associatedabdominal cramping, fever and weight loss. Although the exact cause ofUC is unknown, recent research suggests that the body's natural defensesare operating against proteins in the body which the body thinks areforeign (an “autoimmune reaction”). Perhaps because they resemblebacterial proteins in the gut, these proteins may either instigate orstimulate the inflammatory process that begins to destroy the lining ofthe colon. As the lining of the colon is destroyed, ulcers formreleasing mucus, pus and blood. The disease usually begins in the rectalarea and may eventually extend through the entire large bowel. Repeatedepisodes of inflammation lead to thickening of the wall of the intestineand rectum with scar tissue. Death of colon tissue or sepsis may occurwith severe disease. The symptoms of ulcerative colitis vary in severityand their onset may be gradual or sudden. Attacks may be provoked bymany factors, including respiratory infections or stress.

Although there is currently no cure for UC available, treatments arefocused on suppressing the abnormal inflammatory process in the colonlining. Treatments including corticosteroids immunosuppressives (eg.azathioprine, mercaptopurine, and methotrexate) and aminosalicytates areavailable to treat the disease. However, the long-term use ofimmunosuppressives such as corticosteroids and azathioprine can resultin serious side effects including thinning of bones, cataracts,infection, and liver and bone marrow effects. In the patients in whomcurrent therapies are not successful, surgery is an option. The surgeryinvolves the removal of the entire colon and the rectum.

There are several animal models that can partially mimic chroniculcerative colitis. The most widely used model is the2,4,6-trinitrobenesulfonic acid/ethanol (TNBS) induced colitis model,which induces chronic inflammation and ulceration in the colon. WhenTNBS is introduced into the colon of susceptible mice via intra-rectalinstillation, it induces T-cell mediated immune response in the colonicmucosa, in this case leading to a massive mucosal inflammationcharacterized by the dense infiltration of T-cells and macrophagesthroughout the entire wall of the large bowel. Moreover, thishistopathologic picture is accompanies by the clinical picture ofprogressive weight loss (wasting), bloody diarrhea, rectal prolapse, andlarge bowel wall thickening (Neurath et al. Intern. Rev. Immunol.19:51-62, 2000).

Another colitis model uses dextran sulfate sodium (DSS), which inducesan acute colitis manifested by bloody diarrhea, weight loss, shorteningof the colon and mucosal ulceration with neutrophil infiltration.DSS-induced colitis is characterized histologically by infiltration ofinflammatory cells into the lamina propria, with lymphoid hyperplasia,focal crypt damage, and epithelial ulceration. These changes are thoughtto develop due to a toxic effect of DSS on the epithelium and byphagocytosis of lamina propria cells and production of TNF-alpha andIFN-gamma. Despite its common use, several issues regarding themechanisms of DSS about the relevance to the human disease remainunresolved. DSS is regarded as a T cell-independent model because it isobserved in T cell-deficient animals such as SCID mice.

The administration of anti-IL-31 antibodies or binding partners, solubleIL-31RA comprising polypeptides (including heterodimeric and multimericreceptors), such as IL-31RA-Fc4 or other IL-31RA soluble and fusionproteins to these TNBS or DSS models can be used to evaluate the use ofIL-31 antagonists to ameliorate symptoms and alter the course ofgastrointestinal disease. IL-31 may play a role in the inflammatoryresponse in colitis, and the neutralization of IL-31 activity byadministrating IL-31 antagonists is a potential therapeutic approach forIBD. Other potential therapeutics include IL-31RA polypeptides, solubleheterodimeric and multimeric receptor polypeptides, or anti-IL-31antibodies or binding partners of the present invention, and the like.

4. Psoriasis

Psoriasis is a chronic skin condition that affects more than sevenmillion Americans. Psoriasis occurs when new skin cells grow abnormally,resulting in inflamed, swollen, and scaly patches of skin where the oldskin has not shed quickly enough. Plaque psoriasis, the most commonform, is characterized by inflamed patches of skin (“lesions”) toppedwith silvery white scales. Psoriasis may be limited to a few plaques orinvolve moderate to extensive areas of skin, appearing most commonly onthe scalp, knees, elbows and trunk. Although it is highly visible,psoriasis is not a contagious disease. The pathogenesis of the diseasesinvolves chronic inflammation of the affected tissues. IL-31RApolypeptides, soluble heterodimeric and multimeric receptorpolypeptides, or anti-IL-31 antibodies or binding partners of thepresent invention, and the like, could serve as a valuable therapeuticto reduce inflammation and pathological effects in psoriasis, otherinflammatory skin diseases, skin and mucosal allergies, and relateddiseases.

Psoriasis is a T-cell mediated inflammatory disorder of the skin thatcan cause considerable discomfort. It is a disease for which there is nocure and affects people of all ages. Psoriasis affects approximately twopercent of the populations of European and North America. Althoughindividuals with mild psoriasis can often control their disease withtopical agents, more than one million patients worldwide requireultraviolet or systemic immunosuppressive therapy. Unfortunately, theinconvenience and risks of ultraviolet radiation and the toxicities ofmany therapies limit their long-term use. Moreover, patients usuallyhave recurrence of psoriasis, and in some cases rebound, shortly afterstopping immunosuppressive therapy.

IL-31 was isolated from tissue known to have important immunologicalfunction and which contain cells that play a role in the immune system.IL-31 is expressed in CD3+ selected, activated peripheral blood cells,and it has been shown that IL-31 expression increases after T cellactivation. Moreover, results of experiments described in the Examplessection herein suggest that polypeptides of the present invention canhave an effect on the growth/expansion of monocytes/macrophages,T-cells, B-cells, NK cells and/or differentiated state ofmonocytes/macrophages, T-cells, B-cells, NK cells or these cells'progenitors. Factors that both stimulate proliferation of hematopoieticprogenitors and activate mature cells are generally known, however,proliferation and activation can also require additional growth factors.For example, it has been shown that IL-7 and Steel Factor (c-kit ligand)were required for colony formation of NK progenitors. IL-15+IL-2 incombination with IL-7 and Steel Factor was more effective (Mrózek etal., Blood 87:2632-2640, 1996). However, unidentified cytokines may benecessary for proliferation of specific subsets of NK cells and/or NKprogenitors (Robertson et. al., Blood 76:2451-2438, 1990). Similarly,IL-31 may act alone or in concert or synergy with other cytokines toenhance growth, proliferation expansion and modification ofdifferentiation of monocytes/macrophages, T-cells, B-cells or NK cells.

The present invention provides a method for inhibiting activation ordifferentiation of monocytes/macrophages. Monocytes are incompletelydifferentiated cells that migrate to various tissues where they matureand become macrophages. Macrophages play a central role in the immuneresponse by presenting antigen to lymphocytes and play a supportive roleas accessory cells to lymphocytes by secreting numerous cytokines.Macrophages can internalize extracellular molecules and upon activationhave an increased ability to kill intracellular microorganisms and tumorcells. Activated macrophages are also involved in stimulating acute orlocal inflammation.

The tissue distribution of receptors for a given cytokine offers astrong indication of the potential sites of action of that cytokine.Expression of IL-31RA was seen in monocytes and B-cells, with a dramaticincrease of expression upon activation for CD3+, CD4+, and CD8+ T-cells.In addition, two monocytic cell lines, THP-1 (Tsuchiya et al., Int. J.Cancer 26:171-176, 1980) and U937 (Sundstrom et al., Int. J. Cancer17:565-577, 1976), were also positive for IL-31RA expression.

Expression of OSMR is reported to be very broad (Mosley et al, JBC271:32635-32643, 1996). This distribution of IL-31RA and OSM receptorssupports a role for IL-31 in immune responses, especially expansion ofT-cells upon activation or a role in the monocyte/macrophage arm of theimmune system.

Thus, particular embodiments of the present invention are directedtoward use of soluble IL-31RA/OSMR heterodimers as antagonists ininflammatory and immune diseases or conditions such as pancreatitis,type I diabetes (IDDM), pancreatic cancer, pancreatitis, Graves Disease,inflammatory bowel disease (IBD), Crohn's Disease, colon and intestinalcancer, diverticulosis, autoimmune disease, sepsis, organ or bone marrowtransplant; inflammation due to trauma, surgery or infection;amyloidosis; splenomegaly; graft versus host disease; and whereinhibition of inflammation, immune suppression, reduction ofproliferation of hematopoietic, immune, inflammatory or lymphoid cells,macrophages, T-cells (including Th1 and Th2 cells, CD4+ and CD8+ cells),suppression of immune response to a pathogen or antigen. Moreover thepresence of IL-31RA expression in activated immune cells such asactivated CD4+ and CD19+ cells showed that IL-31RA receptor may beinvolved in the body's immune defensive reactions against foreigninvaders: such as microorganisms and cell debris, and could play a rolein immune responses during inflammation and cancer formation. As such,antibodies and binding partners of the present invention that areagonistic or antagonistic to IL-31RA receptor function, such as IL-31,can be used to modify immune response and inflammation.

IL-31 may find utility in the suppression of the immune system, such asin the treatment of autoimmune diseases, including rheumatoid arthritis,multiple sclerosis, diabetes mellitis, inflammatory bowel disease,Crohn's disease, etc. Immune suppression can also be used to reducerejection of tissue or organ transplants and grafts and to treat T-cell,B-cell or monocyte-specific leukemias or lymphomas, and other cancers,by inhibiting proliferation of the affected cell type. Moreover IL-31can be used to detect monocytes, macrophages, and activated T-cells andaid in the diagnosis of such autoimmune disease, particularly in diseasestates where monocytes are elevated or activated.

IL-31 polypeptides, peptides, antibodies, and the like may also be usedwithin diagnostic systems for the detection of circulating levels ofIL-31. Within a related embodiment, antibodies or other agents thatspecifically bind to IL-31 polypeptides can be used to detectcirculating IL-31 polypeptides. Elevated or depressed levels of ligandpolypeptides may be indicative of pathological conditions, includingcancer. IL-31 polypeptides may contribute to pathologic processes andcan be an indirect marker of an underlying disease.

Moreover, one of skill in the art would recognize that antagonists ofIL-31 are useful. For example, in atherosclerotic lesions, one of thefirst abnormalities is localization of monocyte/macrophages toendothelial cells. These lesions could be prevented by use ofantagonists to IL-31. Anti-IL-31 antibodies (e.g., IL-31 neutralizingantibody), IL-31RA soluble receptors, heterodimers and multimers, andIL-31 binding partners can also be used as antagonists to the IL-31.Moreover, monoblastic leukemia is associated with a variety of clinicalabnormalities that reflect the release of the biologic products of themacrophage, examples include high levels of lysozyme in the serum andurine and high fevers. Moreover, such leukemias exhibit an abnormalincrease of monocytic cells. These effects could possibly be preventedby antagonists to IL-31, such as described herein. Moreover, anti-IL-31can be conjugated to molecules such as toxic moieties and cytokines, asdescribed herein to direct the killing of leukemia monocytic cells.

As IL-31 is expressed in a T-cell, macrophage and monocyte-specificmanner, and these diseases involve abnormalities in monocytic cells,such as cell proliferation, function, localization, and activation, thepolynucleotides, polypeptides, and antibodies of the present inventioncan be used to as diagnostics to detect such monocytic cellabnormalities, and indicate the presence of disease. Such methodsinvolve taking a biological sample from a patient, such as blood,saliva, or biopsy, and comparing it to a normal control sample.Histological, cytological, flow cytometric, biochemical and othermethods can be used to determine the relative levels or localization ofIL-31, or cells expressing IL-31, i.e., monocytes, in the patient samplecompared to the normal control. A change in the level (increase ordecrease) of IL-31 expression, or a change in number or localization ofmonocytes (e.g., increase or infiltration of monocytic cells in tissueswhere they are not normally present) compared to a control would beindicative of disease. Such diagnostic methods can also include usingradiometric, fluorescent, and colorimetric tags attached topolynucleotides, polypeptides or antibodies of the present invention.Such methods are well known in the art and disclosed herein.

IL-31 has been shown to be expressed in activated mononuclear cells, andmay be involved in regulating inflammation. As such, polypeptides of thepresent invention can be assayed and used for their ability to modifyinflammation, or can be used as a marker for inflammation. Methods todetermine proinflammatory and antiinflammatory qualities of IL-31 areknown in the art and discussed herein. Moreover, it may be involved inup-regulating the production of acute phase reactants, such as serumamyloid A (SAA), α1-antichymotrypsin, and haptoglobin, and thatexpression of IL-31RA receptor ligand may be increased upon injection oflipopolysaccharide (LPS) in vivo that are involved in inflammatoryresponse (Dumoutier, L. et al., Proc. Nat'l. Acad. Sci. 97:10144-10149,2000). Production of acute phase proteins, such as SAA, is considered sshort-term survival mechanism where inflammation is beneficial; however,maintenance of acute phase proteins for longer periods contributes tochronic inflammation and can be harmful to human health. For review, seeUhlar, C M and Whitehead, A S, Eur. J. Biochem. 265:501-523, 1999, andBaumann H. and Gauldie, J. Immunology Today 15:74-80, 1994. Moreover,the acute phase protein SAA is implicated in the pathogenesis of severalchronic inflammatory diseases, is implicated in atherosclerosis andrheumatoid arthritis, and is the precursor to the amyloid A proteindeposited in amyloidosis (Uhlar, C M and Whitehead, supra.). Thus, wherea ligand such as IL-31 that acts as a pro-inflammatory molecule andinduces production of SAA, antagonists would be useful in treatinginflammatory disease and other diseases associated with acute phaseresponse proteins induced by the ligand. Such antagonists are providedby the present invention. For example, a method of reducing inflammationcomprises administering to a mammal with inflammation an amount of acomposition of IL-31, or anti-IL-31 antibody (e.g., neutralizingantibody) that is sufficient to reduce inflammation. Moreover, a methodof suppressing an inflammatory response in a mammal with inflammationcan comprise: (1) determining a level of serum amyloid A protein; (2)administering a composition comprising a IL-31 polypeptide or anti-IL-31antibody as described herein in an acceptable pharmaceutical carrier;(3) determining a post administration level of serum amyloid A protein;(4) comparing the level of serum amyloid A protein in step (1) to thelevel of serum amyloid A protein in step (3), wherein a lack of increaseor a decrease in serum amyloid A protein level is indicative ofsuppressing an inflammatory response.

Like IL-31, analysis of the tissue distribution of the mRNAcorresponding it's IL-31RA receptor cDNA showed that mRNA level washighest in monocytes and prostate cells, and is elevated in activatedmonocytes, and activated CD4+, activated CD8+, and activated CD3+ cells.Hence, IL-31RA receptor is also implicated in inducing inflammatory andimmune response. Thus, particular embodiments of the present inventionare directed toward use of IL-31-antibodies, and IL-31, as well assoluble IL-31RA receptor heterodimers as antagonists in inflammatory andimmune diseases or conditions such as, pancreatitis, type I diabetes(IDDM), pancreatic cancer, pancreatitis, Graves Disease, inflammatorybowel disease (IBD), Crohn's Disease, colon and intestinal cancer,diverticulosis, autoimmune disease, sepsis, organ or bone marrowtransplant; inflammation due to trauma, surgery or infection;amyloidosis; splenomegaly; graft versus host disease; and whereinhibition of inflammation, immune suppression, reduction ofproliferation of hematopoietic, immune, inflammatory or lymphoid cells,macrophages, T-cells (including Th1 and Th2 cells, CD4+ and CD8+ cells),suppression of immune response to a pathogen or antigen. Moreover thepresence of IL-31RA receptor and IL-31 expression in activated immunecells such as activated CD3+, monocytes, CD4+ and CD19+ cells showedthat IL-31RA receptor may be involved in the body's immune defensivereactions against foreign invaders: such as microorganisms and celldebris, and could play a role in immune responses during inflammationand cancer formation. As such, IL-31 and IL-31-antibodies of the presentinvention that are agonistic or antagonistic to IL-31RA receptorfunction, can be used to modify immune response and inflammation.

IL-31 polypeptides that bind IL-31RA receptor polypeptides, andantibodies thereto are useful to:

1) Antagonize or block signaling via IL-31RA-comprising receptors in thetreatment of acute inflammation, inflammation as a result of trauma,tissue injury, surgery, sepsis or infection, and chronic inflammatorydiseases such as asthma, inflammatory bowel disease (IBD), chroniccolitis, splenomegaly, rheumatoid arthritis, recurrent acuteinflammatory episodes (e.g., tuberculosis), and treatment ofamyloidosis, and atherosclerosis, Castleman's Disease, asthma, and otherdiseases associated with the induction of acute-phase response.

2) Antagonize or block signaling via the IL-31RA receptor receptors inthe treatment of autoimmune diseases such as IDDM, multiple sclerosis(MS), systemic Lupus erythematosus (SLE), myasthenia gravis, rheumatoidarthritis, and IBD to prevent or inhibit signaling in immune cells (e.g.lymphocytes, monocytes, leukocytes) via IL-31RA receptor (Hughes C etal., J. Immunol 153: 3319-3325, 1994). Alternatively antibodies, such asmonoclonal antibodies (MAb) to IL-31, can also be used as an antagonistto deplete unwanted immune cells to treat autoimmune disease. Asthma,allergy and other atopic disease may be treated with an MAb against, forexample, anti-IL-31 antibodies, soluble IL-31RA receptor solublereceptors or IL-31RA/CRF2-4 heterodimers, to inhibit the immune responseor to deplete offending cells. Blocking or inhibiting signaling viaIL-31RA, using the polypeptides and antibodies of the present invention,may also benefit diseases of the pancreas, kidney, pituitary andneuronal cells. IDDM, NIDDM, pancreatitis, and pancreatic carcinoma maybenefit. IL-31RA may serve as a target for MAb therapy of cancer wherean antagonizing MAb inhibits cancer growth and targets immune-mediatedkilling. (Holliger P, and Hoogenboom, H: Nature Biotech. 16: 1015-1016,1998). Mabs to soluble IL-31RA receptor monomers, homodimers,heterodimers and multimers may also be useful to treat nephropathiessuch as glomerulosclerosis, membranous neuropathy, amyloidosis (whichalso affects the kidney among other tissues), renal arteriosclerosis,glomerulonephritis of various origins, fibroproliferative diseases ofthe kidney, as well as kidney dysfunction associated with SLE, IDDM,type II diabetes (NIDDM), renal tumors and other diseases.

3) Agonize or initiate signaling via the IL-31RA receptors in thetreatment of autoimmune diseases such as IDDM, MS, SLE, myastheniagravis, rheumatoid arthritis, and IBD. IL-31 may signal lymphocytes orother immune cells to differentiate, alter proliferation, or changeproduction of cytokines or cell surface proteins that ameliorateautoimmunity. Specifically, modulation of a T-helper cell response to analternate pattern of cytokine secretion may deviate an autoimmuneresponse to ameliorate disease (Smith J A et al., J. Immunol.160:4841-4849, 1998). Similarly, IL-31 may be used to signal, depleteand deviate immune cells involved in asthma, allergy and atopoicdisease. Signaling via IL-31RA receptor may also benefit diseases of thepancreas, kidney, pituitary and neuronal cells. IDDM, NIDDM,pancreatitis, and pancreatic carcinoma may benefit. IL-31RA may serve asa target for MAb therapy of pancreatic cancer where a signaling MAbinhibits cancer growth and targets immune-mediated killing (Tutt, A L etal., J Immunol. 161: 3175-3185, 1998). Similarly T-cell specificleukemias, lymphomas, plasma cell dyscrasia (e.g., multiple myeloma),and carcinoma may be treated with monoclonal antibodies (e.g.,neutralizing antibody) to IL-31RA-comprising soluble receptors of thepresent invention.

Anti-IL-31 antibodies, soluble IL-31RA receptor monomeric, homodimeric,heterodimeric and multimeric polypeptides described herein can be usedto neutralize/block IL-31RA receptor ligand activity in the treatment ofautoimmune disease, atopic disease, NIDDM, pancreatitis and kidneydysfunction as described above.

Anti-IL-31 antibodies, and soluble IL-31RA-comprising receptors areuseful as antagonists of IL-31. Such antagonistic effects can beachieved by direct neutralization or binding of its natural ligand. Inaddition to antagonistic uses, the soluble receptors can bind IL-31 andact as carrier or carrier proteins, in order to transport IL-31 todifferent tissues, organs, and cells within the body. As such, thesoluble receptors can be fused or coupled to molecules, polypeptides orchemical moieties that direct the soluble-receptor-Ligand complex to aspecific site, such as a tissue, specific immune cell, monocytes, ortumor. For example, in acute infection or some cancers, benefit mayresult from induction of inflammation and local acute phase responseproteins. Thus, the soluble receptors described herein or antibodies ofthe present invention can be used to specifically direct the action of apro-inflammatory IL-31 ligand. See, Cosman, D. Cytokine 5: 95-106, 1993;and Fernandez-Botran, R. Exp. Opin. Invest. Drugs 9:497-513, 2000.

Generally, the dosage of administered IL-31 polypeptide (or IL-31RAanalog or fusion protein) will vary depending upon such factors as thepatient's age, weight, height, sex, general medical condition andprevious medical history. Typically, it is desirable to provide therecipient with a dosage of IL-31 polypeptide which is in the range offrom about 1 pg/kg to 10 mg/kg (amount of agent/body weight of patient),although a lower or higher dosage also may be administered ascircumstances dictate. One skilled in the art can readily determine suchdosages, and adjustments thereto, using methods known in the art.

Administration of a IL-31 polypeptide to a subject can be topical,inhalant, intravenous, intraarterial, intraperitoneal, intramuscular,subcutaneous, intrapleural, intrathecal, by perfusion through a regionalcatheter, or by direct intralesional injection. When administeringtherapeutic proteins by injection, the administration may be bycontinuous infusion or by single or multiple boluses.

Additional routes of administration include oral, mucosal-membrane,pulmonary, and transcutaneous. Oral delivery is suitable for polyestermicrospheres, zein microspheres, proteinoid microspheres,polycyanoacrylate microspheres, and lipid-based systems (see, forexample, DiBase and Morrel, “Oral Delivery of MicroencapsulatedProteins,” in Protein Delivery: Physical Systems, Sanders and Hendren(eds.), pages 255-288 (Plenum Press 1997)). The feasibility of anintranasal delivery is exemplified by such a mode of insulinadministration (see, for example, Hinchcliffe and Ilium, Adv. DrugDeliv. Rev. 35:199 (1999)). Dry or liquid particles comprising IL-31 canbe prepared and inhaled with the aid of dry-powder dispersers, liquidaerosol generators, or nebulizers (e.g., Pettit and Gombotz, TIBTECH16:343 (1998); Patton et al., Adv. Drug Deliv. Rev. 35:235 (1999)). Thisapproach is illustrated by the AERX diabetes management system, which isa hand-held electronic inhaler that delivers aerosolized insulin intothe lungs. Studies have shown that proteins as large as 48,000 kDa havebeen delivered across skin at therapeutic concentrations with the aid oflow-frequency ultrasound, which illustrates the feasibility oftrascutaneous administration (Mitragotri et al., Science 269:850(1995)). Transdermal delivery using electroporation provides anothermeans to administer a molecule having IL-31 binding activity (Potts etal., Pharm. Biotechnol. 10:213 (1997)).

A pharmaceutical composition comprising a protein, polypeptide, orpeptide having IL-31 binding activity can be formulated according toknown methods to prepare pharmaceutically useful compositions, wherebythe therapeutic proteins are combined in a mixture with apharmaceutically acceptable carrier. A composition is said to be a“pharmaceutically acceptable carrier” if its administration can betolerated by a recipient patient. Sterile phosphate-buffered saline isone example of a pharmaceutically acceptable carrier. Other suitablecarriers are well-known to those in the art. See, for example, Gennaro(ed.), Remington's Pharmaceutical Sciences, 19th Edition (MackPublishing Company 1995).

For purposes of therapy, molecules having IL-31 binding activity and apharmaceutically acceptable carrier are administered to a patient in atherapeutically effective amount. A combination of a protein,polypeptide, or peptide having IL-31 binding activity and apharmaceutically acceptable carrier is said to be administered in a“therapeutically effective amount” if the amount administered isphysiologically significant. An agent is physiologically significant ifits presence results in a detectable change in the physiology of arecipient patient. For example, an agent used to treat inflammation isphysiologically significant if its presence alleviates at least aportion of the inflammatory response.

A pharmaceutical composition comprising IL-31 (or IL-31 analog or fusionprotein) can be furnished in liquid form, in an aerosol, or in solidform. Liquid forms, are illustrated by injectable solutions, aerosols,droplets, topological solutions and oral suspensions. Exemplary solidforms include capsules, tablets, and controlled-release forms. Thelatter form is illustrated by miniosmotic pumps and implants (Bremer etal., Pharm. Biotechnol. 10:239 (1997); Ranade, “Implants in DrugDelivery,” in Drug Delivery Systems, Ranade and Hollinger (eds.), pages95-123 (CRC Press 1995); Bremer et al., “Protein Delivery with InfusionPumps,” in Protein Delivery: Physical Systems, Sanders and Hendren(eds.), pages 239-254 (Plenum Press 1997); Yewey et al., “Delivery ofProteins from a Controlled Release Injectable Implant,” in ProteinDelivery: Physical Systems, Sanders and Hendren (eds.), pages 93-117(Plenum Press 1997)). Other solid forms include creams, pastes, othertopological applications, and the like.

The anti-IL-31 antibodies disclosed herein may also be formulated asimmunoliposomes. Liposomes containing the antibody are prepared bymethods known in the art, such as described in Epstein et al., Proc.Natl. Acad. Sci. USA, 82: 3688 (1985); Hwang et al., Proc. Natl. Acad.Sci. USA, 77: 4030 (1980); and U.S. Pat. Nos. 4,485,045 and 4,544,545.Liposomes with enhanced circulation time are disclosed in U.S. Pat. No.5,013,556.

Particularly useful liposomes can be generated by the reverse phaseevaporation method with a lipid composition comprisingphosphatidylcholine, cholesterol and PEG-derivatizedphosphatidylethanolamine (PEG-PE). Liposomes are extruded-throughfilters of defined pore size to yield liposomes with the desireddiameter. Fab′ fragments of the antibody of the present invention can beconjugated to the liposomes as described in Martin et al. J. Biol. Chem.257: 286-288 (1982) via a disulfide interchange reaction. Achemotherapeutic agent (such as Doxorubicin) is optionally containedwithin the liposome. See Gabizon et al. J. National Cancer Inst. 81(19)1484 (1989).

Therapeutic formulations of the antibody are prepared for storage bymixing the antibody having the desired degree of purity with optionalphysiologically acceptable carriers, excipients or stabilizers(Remington's Pharmaceutical Sciences 16th edition, Osol, A. Ed. (1980)),in the form of lyophilized formulations or aqueous solutions. Acceptablecarriers, excipients, or stabilizers are nontoxic to recipients at thedosages and concentrations employed, and include buffers such asphosphate, citrate, and other organic acids; antioxidants includingascorbic acid and methionine; preservatives (such asoctadecyldimethylbenzyl ammonium chloride; hexamethonium chloride;benzalkonium chloride, benzethonium chloride; phenol, butyl or benzylalcohol; alkyl parabens such as methyl or propyl paraben; catechol;resorcinol; cyclohexanol; 3-pentanol; and m-cresol); low molecularweight (less than about 10 residues) polypeptides; proteins, such asserum albumin, gelatin, or immunoglobulins; hydrophilic polymers such aspolyvinylpyrrolidone; amino acids such as glycine, glutamine,asparagine, histidine, arginine, or lysine; monosaccharides,disaccharides, and other carbohydrates including glucose, mannose, ordextrins; chelating agents such as EDTA; sugars such as sucrose,mannitol, trehalose or sorbitol; salt-forming counter-ions such assodium; metal complexes (e.g. Zn-protein complexes); and/or non-ionicsurfactants such as Tween™, Pluronics™ or polyethylene glycol (PEG).

The formulation herein may also contain more than one active compound asnecessary for the particular indication being treated, preferably thosewith complementary activities that do not adversely affect each other.For example, it may be desirable to further provide antibodies whichbind to IL-31 in the one formulation. Alternatively, or in addition, thecomposition may comprise a chemotherapeutic agent or a cytokine. Suchmolecules are suitably present in combination in amounts that areeffective for the purpose intended.

The active ingredients may also be entrapped in microcapsules prepared,for example, by coacervation techniques or by interfacialpolymerization, for example, hydroxymethylcellulose orgelatin-microcapsules and poly-(methylmethacylate) microcapsules,respectively, in colloidal drug delivery systems (for example,liposomes, albumin microspheres, macroemulsions, nano-particles andnanocapsules) or in macroemulsions. Such techniques are disclosed inRemington's Pharmaceutical Sciences 16th edition, Osol, A. Ed. (1980).

The formulations to be used for in vivo administration must be sterile.This is readily accomplished by filtration through sterile filtrationmembranes.

Sustained-release preparations may be prepared. Suitable examples ofsustained-release preparations include semipermeable matrices of solidhydrophobic polymers containing the antibody, which matrices are in theform of shaped articles, e.g. films, or microcapsules. Examples ofsustained-release matrices include polyesters, hydrogels (for example,poly(2-hydroxyethyl-methacrylate), or poly(vinylalcohol)), polylactides(U.S. Pat. No. 3,773,919), copolymers of L-glutamic acid and .gamma.ethyl-L-glutamate, non-degradable ethylene-vinyl acetate, degradablelactic acid-glycolic acid copolymers such as the Lupron Depot™(injectable microspheres composed of lactic acid-glycolic acid copolymerand leuprolide acetate), and poly-D-(−)-3-hydroxybutyric acid. Whilepolymers such as ethylene-vinyl acetate and lactic acid-glycolic acidenable release of molecules for over 100 days, certain hydrogels releaseproteins for shorter time periods. When encapsulated antibodies remainin the body for a long time, they may denature or aggregate as a resultof exposure to moisture at 37° C., resulting in a loss of biologicalactivity and possible changes in immunogenicity. Rational strategies canbe devised for stabilization depending on the mechanism involved. Forexample, if the aggregation mechanism is discovered to be intermolecularS—S bond formation through thio-disulfide interchange, stabilization maybe achieved by modifying sulfhydryl residues, lyophilizing from acidicsolutions, controlling moisture content, using appropriate additives,and developing specific polymer matrix compositions.

Liposomes provide one means to deliver therapeutic polypeptides to asubject intravenously, intraperitoneally, intrathecally,intramuscularly, subcutaneously, or via oral administration, inhalation,or intranasal administration. Liposomes are microscopic vesicles thatconsist of one or more lipid bilayers surrounding aqueous compartments(see, generally, Bakker-Woudenberg et al., Eur. J. Clin. Microbiol.Infect. Dis. 12 (Suppl. 1):S61 (1993), Kim, Drugs 46:618 (1993), andRanade, “Site-Specific Drug Delivery Using Liposomes as Carriers,” inDrug Delivery Systems, Ranade and Hollinger (eds.), pages 3-24 (CRCPress 1995)). Liposomes are similar in composition to cellular membranesand as a result, liposomes can be administered safely and arebiodegradable. Depending on the method of preparation, liposomes may beunilamellar or multilamellar, and liposomes can vary in size withdiameters ranging from 0.02 μm to greater than 10 μm. A variety ofagents can be encapsulated in liposomes: hydrophobic agents partition inthe bilayers and hydrophilic agents partition within the inner aqueousspace(s) (see, for example, Machy et al., Liposomes In Cell Biology AndPharmacology (John Libbey 1987), and Ostro et al., American J. Hosp.Pharm. 46:1576 (1989)). Moreover, it is possible to control thetherapeutic availability of the encapsulated agent by varying liposomesize, the number of bilayers, lipid composition, as well as the chargeand surface characteristics of the liposomes.

Liposomes can adsorb to virtually any type of cell and then slowlyrelease the encapsulated agent. Alternatively, an absorbed liposome maybe endocytosed by cells that are phagocytic. Endocytosis is followed byintralysosomal degradation of liposomal lipids and release of theencapsulated agents (Scherphof et al., Ann. N.Y. Acad. Sci. 446:368(1985)). After intravenous administration, small liposomes (0.1 to 1.0μm) are typically taken up by cells of the reticuloendothelial system,located principally in the liver and spleen, whereas liposomes largerthan 3.0 μm are deposited in the lung. This preferential uptake ofsmaller liposomes by the cells of the reticuloendothelial system hasbeen used to deliver chemotherapeutic agents to macrophages and totumors of the liver.

The reticuloendothelial system can be circumvented by several methodsincluding saturation with large doses of liposome particles, orselective macrophage inactivation by pharmacological means (Claassen etal., Biochim. Biophys. Acta 802:428 (1984)). In addition, incorporationof glycolipid- or polyethelene glycol-derivatized phospholipids intoliposome membranes has been shown to result in a significantly reduceduptake by the reticuloendothelial system (Allen et al., Biochim.Biophys. Acta 1068:133 (1991); Allen et al., Biochim. Biophys. Acta1150:9 (1993)).

Liposomes can also be prepared to target particular cells or organs byvarying phospholipid composition or by inserting receptors or ligandsinto the liposomes. For example, liposomes, prepared with a high contentof a nonionic surfactant, have been used to target the liver (Hayakawaet al., Japanese Patent 04-244,018; Kato et al., Biol. Pharm. Bull.16:960 (1993)). These formulations were prepared by mixing soybeanphospatidylcholine, α-tocopherol, and ethoxylated hydrogenated castoroil (HCO-60) in methanol, concentrating the mixture under vacuum, andthen reconstituting the mixture with water. A liposomal formulation ofdipalmitoylphosphatidylcholine (DPPC) with a soybean-derivedsterylglucoside mixture (SG) and cholesterol (Ch) has also been shown totarget the liver (Shimizu et al., Biol. Pharm. Bull. 20:881 (1997)).

Alternatively, various targeting ligands can be bound to the surface ofthe liposome, such as antibodies, antibody fragments, carbohydrates,vitamins, and transport proteins. For example, liposomes can be modifiedwith branched type galactosyllipid derivatives to targetasialoglycoprotein (galactose) receptors, which are exclusivelyexpressed on the surface of liver cells (Kato and Sugiyama, Crit. Rev.Ther. Drug Carrier Syst. 14:287 (1997); Murahashi et al., Biol. Pharm.Bull. 20:259 (1997)). Similarly, Wu et al., Hepatology 27:772 (1998),have shown that labeling liposomes with asialofetuin led to a shortenedliposome plasma half-life and greatly enhanced uptake ofasialofetuin-labeled liposome by hepatocytes. On the other hand, hepaticaccumulation of liposomes comprising branched type galactosyllipidderivatives can be inhibited by preinjection of asialofetuin (Murahashiet al., Biol. Pharm. Bull. 20:259 (1997)). Polyaconitylated human serumalbumin liposomes provide another approach for targeting liposomes toliver cells (Kamps et al., Proc. Nat'l Acad. Sci. USA 94:11681 (1997)).Moreover, Geho, et al. U.S. Pat. No. 4,603,044, describe ahepatocyte-directed liposome vesicle delivery system, which hasspecificity for hepatobiliary receptors associated with the specializedmetabolic cells of the liver.

Polypeptides having IL-31 binding activity can be encapsulated withinliposomes using standard techniques of protein microencapsulation (see,for example, Anderson et al., Infect. Immun. 31:1099 (1981), Anderson etal., Cancer Res. 50:1853 (1990), and Cohen et al., Biochim. Biophys.Acta 1063:95 (1991), Alving et al. “Preparation and Use of Liposomes inImmunological Studies,” in Liposome Technology, 2nd Edition, Vol. III,Gregoriadis (ed.), page 317 (CRC Press 1993), Wassef et al., Meth.Enzymol. 149:124 (1987)). As noted above, therapeutically usefulliposomes may contain a variety of components. For example, liposomesmay comprise lipid derivatives of poly(ethylene glycol) (Allen et al.,Biochim. Biophys. Acta 1150:9 (1993)).

Degradable polymer microspheres have been designed to maintain highsystemic levels of therapeutic proteins. Microspheres are prepared fromdegradable polymers such as poly(lactide-co-glycolide) (PLG),polyanhydrides, poly(ortho esters), nonbiodegradable ethylvinyl acetatepolymers, in which proteins are entrapped in the polymer (Gombotz andPettit, Bioconjugate Chem. 6:332 (1995); Ranade, “Role of Polymers inDrug Delivery,” in Drug Delivery Systems, Ranade and Hollinger (eds.),pages 51-93 (CRC Press 1995); Roskos and Maskiewicz, “DegradableControlled Release Systems Useful for Protein Delivery,” in ProteinDelivery: Physical Systems, Sanders and Hendren (eds.), pages 45-92(Plenum Press 1997); Bartus et al., Science 281:1161 (1998); Putney andBurke, Nature Biotechnology 16:153 (1998); Putney, Curr. Opin. Chem.Biol. 2:548 (1998)). Polyethylene glycol (PEG)-coated nanospheres canalso provide carriers for intravenous administration of therapeuticproteins (see, for example, Gref et al., Pharm. Biotechnol. 10:167(1997)).

Other dosage forms can be devised by those skilled in the art, as shown,for example, by Ansel and Popovich, Pharmaceutical Dosage Forms and DrugDelivery Systems, 5^(th) Edition (Lea & Febiger 1990), Gennaro (ed.),Remington's Pharmaceutical Sciences, 19^(th) Edition (Mack PublishingCompany 1995), and by Ranade and Hollinger, Drug Delivery Systems (CRCPress 1996).

As an illustration, pharmaceutical compositions may be supplied as a kitcomprising a container that comprises a IL-31 polypeptide or a IL-31antagonist (e.g., an antibody or antibody fragment that binds a IL-31polypeptide). Therapeutic polypeptides can be provided in the form of aninjectable solution for single or multiple doses, or as a sterile powderthat will be reconstituted before injection. Alternatively, such a kitcan include a dry-powder disperser, liquid aerosol generator, ornebulizer for administration of a therapeutic polypeptide.

Within one aspect the invention provides a monoclonal antibodycomprising an monoclonal antibody that specifically binds a polypeptidecomprising the amino acid sequence of SEQ ID NO: 2 wherein thepolypeptide is capable of binding the monoclonal antibody produced bythe hybridoma deposited with the American Type Culture Collection havingthe ATCC Patent Deposit Designation selected from: a) ATCC PatentDeposit Designation PTA-6815; b) ATCC Patent Deposit DesignationPTA-6816; c) ATCC Patent Deposit Designation PTA-6829; d) ATCC PatentDeposit Designation PTA-6830; e) ATCC Patent Deposit DesignationPTA-6831; f) ATCC Patent Deposit Designation PTA-6871; g) ATCC PatentDeposit Designation PTA-6872; h) ATCC Patent Deposit DesignationPTA-6875; and i) ATCC Patent Deposit Designation PTA-6873. Within anembodiment, the antibody neutralizes the interaction of IL-31 (SEQ IDNO:2) with IL-31RA (SEQ ID NO:5). Within another embodiment, theantibody is (a) a murine monoclonal antibody, (b) a humanized antibodyderived from (a), or (c) an antibody fragment, or (d) a human monoclonalantibody. Within another embodiment the antibody further comprises aradionuclide, enzyme, substrate, cofactor, fluorescent marker,chemiluminescent marker, peptide tag, magnetic particle, or toxin.Within another embodiment the antibody further comprises PEGylation.Within another embodiment the antibody is a neutralizing antibody.Within another embodiment administration of the antibody to a mammalinhibits, prevents, reduces or blocks the pro-inflammatory activity ofthe polypeptide. Within another embodiment administration of theantibody to a mammal inhibits, prevents, reduces or blocks thescratching and dermatitis associated with the proinflammatory activityof the polypeptide.

Within another aspect the invention provides a monoclonal antibody thatspecifically binds a polypeptide comprising the amino acid sequence ofSEQ ID NO: 2 wherein the polypeptide is capable of binding themonoclonal antibody produced by the hybridoma deposited with theAmerican Type Culture Collection having the ATCC Patent DepositDesignation selected from: a) ATCC Patent Deposit Designation PTA-6815;b) ATCC Patent Deposit Designation PTA-6816; c) ATCC Patent DepositDesignation PTA-6871; d) ATCC Patent Deposit Designation PTA-6829; ande) ATCC Patent Deposit Designation PTA-6830.

Within another aspect the invention provides a monoclonal antibody thatspecifically binds a polypeptide comprising the amino acid sequence ofSEQ ID NO: 2 wherein the polypeptide is capable of binding themonoclonal antibody produced by the hybridoma deposited with theAmerican Type Culture Collection having the ATCC Patent DepositDesignation selected from: a) ATCC Patent Deposit Designation PTA-6815;b) ATCC Patent Deposit Designation PTA-6816; and c) ATCC Patent DepositDesignation PTA-6871.

Within another aspect the invention provides a monoclonal antibody thatspecifically binds a polypeptide comprising the amino acid sequence ofSEQ ID NO: 2 wherein the polypeptide is capable of binding themonoclonal antibody produced by the hybridoma deposited with theAmerican Type Culture Collection having the ATCC Patent DepositDesignation selected from: a) ATCC Patent Deposit Designation PTA-6829;and b) ATCC Patent Deposit Designation PTA-6830.

Within another aspect is provided a monoclonal antibody thatspecifically binds a polypeptide comprising the amino acid sequence ofSEQ ID NO: 2 wherein the polypeptide is capable of binding themonoclonal antibody produced by the hybridoma deposited with theAmerican Type Culture Collection having the ATCC Patent DepositDesignation selected from: a) ATCC Patent Deposit Designation PTA-6872;and b) ATCC Patent Deposit Designation PTA-6875.

Within another aspect is provided a monoclonal antibody thatspecifically binds a polypeptide comprising the amino acid sequence ofSEQ ID NO:4 wherein the polypeptide is capable of binding the monoclonalantibody produced by the hybridoma deposited with the American TypeCulture Collection having the ATCC Patent Deposit Designation PTA-6874.Within an embodiment the antibody is a neutralizing antibody. Within anembodiment administration of the antibody to a mammal inhibits,prevents, reduces or blocks the pro-inflammatory activity of thepolypeptide. Within an embodiment administration of the antibody to amammal inhibits, prevents, reduces or blocks the scratching anddermatitis associated with the proinflammatory activity of thepolypeptide.

Within another aspect the invention provides a method of reducinginflammation in a mammal comprising administering to the mammal anamount of the IL-31 antibodies described herein, whereby theinflammation is reduced.

Within another aspect the invention provides a method of treating amammal afflicted with an inflammatory disease in which IL-31 plays arole, comprising: administering an antagonist of IL-31 to the mammalsuch that the inflammation is reduced, wherein the antagonist comprises(i) an antibody, antibody fragment, or binding polypeptide thatspecifically binds a polypeptide or polypeptide fragment of IL-31RA or(ii) a polypeptide or polypeptide fragment of IL-31RA; and wherein theinflammatory activity of IL-31 is reduced. Within an embodiment thedisease is a inflammatory disease comprises pruritic diseases. Within anembodiment the disease is atopic dermatitis. Within an embodiment thedisease is prurigo nodularis.

Within another aspect the invention provides a method of reducing,inhibiting, or preventing the effect of pruritis in a mammal in whichIL-31 plays a role, comprising: administering an antagonist of IL-31 tothe mammal such that the pruritis is reduced, wherein the antagonistcomprises (i) an antibody, antibody fragment, or binding polypeptidethat specifically binds a polypeptide or polypeptide fragment of thepolypeptide comprising the amino acid sequence of SEQ ID NO:2, or afragment thereof; and wherein the pruritic activity of IL-31 is reduced.Within an embodiment the disease of the mammal is atopic dermatitis.Within an embodiment the disease of the mammal is dermatitis. Within anembodiment the antibody is an antibody as described herein.

Within another aspect the invention provides a method of reducing,inhibiting, or preventing the effect of pruritis in a mammal in whichIL-31 plays a role, comprising: administering an antagonist of IL-31 tothe mammal such that the there is a reduction in itch in the mammalwherein the antagonist comprises (i) an antibody, antibody fragment, orbinding polypeptide that specifically binds a polypeptide or polypeptidefragment of the polypeptide comprising the amino acid sequence of SEQ IDNO:2, or a fragment thereof; and whereby the scratching activity ofIL-31 is reduced. Within an embodiment the disease of the mammal isatopic dermatitis. Within an embodiment the disease of the mammal isdermatitis. Within an embodiment the antibody is an antibody asdescribed herein.

Within another aspect the invention provides a monoclonal antibody thatspecifically binds a polypeptide comprising the amino acid sequence ofSEQ ID NO: 2, wherein the polypeptide is capable of binding themonoclonal antibody produced by the hybridoma clone designation numberselected from: a) clone 292.12.3.1 (ATCC Patent Deposit DesignationPTA-6815); b) clone 292.63.5.3 (ATCC Patent Deposit DesignationPTA-6829); c) clone 292.72.3.1 (ATCC Patent Deposit DesignationPTA-6816); d) clone 292.84.1.6 (ATCC Patent Deposit DesignationPTA-6871); and e) clone 292.118.6.4 (ATCC Patent Deposit DesignationPTA-6830).

Within another aspect the invention provides a monoclonal antibody thatspecifically binds a polypeptide comprising the amino acid sequence ofSEQ ID NO: 2, wherein the polypeptide is capable of binding themonoclonal antibody produced by the hybridoma clone designation numberselected from: a) clone 294.35.2.6.3 (ATCC Patent Deposit DesignationPTA-6872); b) clone 294.144.3.5 (ATCC Patent Deposit DesignationPTA-6873); c) clone 294.154.5.6 ATCC Patent Deposit DesignationPTA-6875); and d) clone 294.163.2.1 (ATCC Patent Deposit DesignationPTA-6831).

Within another aspect the invention provides a monoclonal antibodycomprising an monoclonal antibody that is capable of competing forbinding a polypeptide comprising the amino acid sequence of SEQ ID NO: 2wherein the polypeptide is capable of binding the monoclonal antibodyproduced by the hybridoma deposited with the American Type CultureCollection having the ATCC Patent Deposit Designation selected from: a)ATCC Patent Deposit Designation PTA-6815; b) ATCC Patent DepositDesignation PTA-6816; c) ATCC Patent Deposit Designation PTA-6829; d)ATCC Patent Deposit Designation PTA-6830; e) ATCC Patent DepositDesignation PTA-6831; ATCC Patent Deposit Designation PTA-6871; g) ATCCPatent Deposit Designation PTA-6872; h) ATCC Patent Deposit DesignationPTA-6875; and i) ATCC Patent Deposit Designation PTA-6873.

Within another aspect is provided a hybridoma, wherein the hybridoma isdeposited with the American Type Culture Collection having the ATCCPatent Deposit Designation selected from: a) ATCC Patent DepositDesignation PTA-6815; b) ATCC Patent Deposit Designation PTA-6816; c)ATCC Patent Deposit Designation PTA-6829; d) ATCC Patent DepositDesignation PTA-6830; e) ATCC Patent Deposit Designation PTA-6831; f)ATCC Patent Deposit Designation PTA-6871; g) ATCC Patent DepositDesignation PTA-6872; h) ATCC Patent Deposit Designation PTA-6875; andi) ATCC Patent Deposit Designation PTA-6873.

Within another aspect the present invention provides a method ofproducing an antibody to a IL-31 polypeptide comprising: inoculating ananimal with a polypeptide selected from the group consisting of: (a) apolypeptide consisting of 9 to 141 amino acids, wherein the polypeptideis identical to a contiguous sequence of amino acid residues in SEQ IDNO:2 from amino acid number 24 (Ser) to amino acid number 164 (Thr); apolypeptide as disclosed above; (c) a polypeptide comprising the aminoacid sequence of SEQ ID NO:2 from amino acid number 38-52; (d) apolypeptide comprising the amino acid sequence of SEQ ID NO:2 from aminoacid number 83-98; (e) a polypeptide comprising the amino acid sequenceof SEQ ID NO:2 from amino acid number 104-117; (f) a polypeptidecomprising the amino acid sequence of SEQ ID NO:2 from amino acid number137-152; (g) a polypeptide comprising the amino acid sequence of SEQ IDNO:2 from amino acid number 38-152; (h) a polypeptide comprising theamino acid sequence of SEQ ED NO:2 from amino acid number 24-164; (c) apolypeptide comprising the amino acid sequence of SEQ ID NO:4 from aminoacid number 38-52; (d) a polypeptide comprising the amino acid sequenceof SEQ ID NO:4 from amino acid number 85-98; (e) a polypeptidecomprising the amino acid sequence of SEQ ID NO:4 from amino acid number104-118; (f) a polypeptide comprising the amino acid sequence of SEQ IDNO:4 from amino acid number 141-157; (g) a polypeptide comprising theamino acid sequence of SEQ ID NO:4 from amino acid number 38-157; (h) apolypeptide comprising the amino acid sequence of SEQ ID NO:4 from aminoacid number 24-163; (i) a polypeptide comprising an antigenic epitopeaccording to a Hopp/Woods hydrophilicity profile of SEQ ID NO:2 or SEQID NO:4, wherein the profile is based on a sliding six-residue window.Buried G, S, and T residues and exposed H, Y, and W residues ignored;and wherein the polypeptide elicits an immune response in the animal toproduce the antibody; and isolating the antibody from the animal.

Within another aspect the present invention provides an antibody (e.g.,neutralizing antibody) produced by the method as disclosed above,wherein the antibody binds to a polypeptide of SEQ ID NO:2 or SEQ IDNO:4. In one embodiment, the antibody disclosed above specifically bindsto a polypeptide shown in SEQ ID NO:2 or SEQ ID NO:4.

Within another aspect the present invention provides a method ofdetecting the presence of IL-31 in a biological sample, comprising thesteps of: (a) contacting the biological sample with an antibody, or anantibody fragment as disclosed above, wherein the contacting isperformed under conditions that allow the binding of the antibody orantibody fragment to the biological sample, and (b) detecting any of thebound antibody or bound antibody fragment.

Within another aspect, the present invention provides a method ofkilling cancer cells comprising, obtaining ex vivo a tissue orbiological sample containing cancer cells from a patient, or identifyingcancer cells in vivo; producing a polypeptide by the method as disclosedherein; formulating the polypeptide in a pharmaceutically acceptablevehicle; and administering to the patient or exposing the cancer cellsto the polypeptide; wherein the polypeptide kills the cells. In oneembodiment the method of killing cancer cells is as disclosed above,wherein the polypeptide is further conjugated to a toxin. In oneembodiment the antibody is as disclosed above, wherein the antibody isselected from the group consisting of: (a) polyclonal antibody, (b)murine monoclonal antibody, (c) humanized antibody derived from (b), (d)an antibody fragment, and (e) human monoclonal antibody.

Within another aspect, the present invention provides an antibody orantibody fragment that specifically binds to a polypeptide of comprisinga sequence of amino acid residues selected from the group consisting of:(a) the polypeptide shown from residues 38 (Val) to 152 (Leu) as shownin SEQ ID NO:2; (b) the polypeptide shown from residues 27 (Leu) to 164(Thr) as shown in SEQ ID NO:2; (c) the polypeptide shown from residues24 (Thr) to 164 (Thr) as shown in SEQ ID NO:2; and (d) the polypeptideshown from residues 1 (Met) to 164 (Thr) as shown in SEQ ID NO:2. Inanother embodiment the antibody is as disclosed above, wherein theantibody further comprises a radionuclide, enzyme, substrate, cofactor,fluorescent marker, chemiluminescent marker, peptide tag, magneticparticle, drug, or toxin.

Within another aspect, the present invention provides a method forinhibiting IL-31-induced proliferation or differentiation ofhematopoietic cells and hematopoietic cell progenitors comprisingculturing bone marrow or peripheral blood cells with a compositioncomprising an amount of an antibody as disclosed herein sufficient toreduce proliferation or differentiation of the hematopoietic cells inthe bone marrow or peripheral blood cells as compared to bone marrow orperipheral blood cells cultured in the absence of soluble cytokinereceptor. In one embodiment the method for inhibiting IL-31-inducedproliferation or differentiation of hematopoietic cells andhematopoietic cell progenitors is as disclosed above, wherein thehematopoietic cells and hematopoietic progenitor cells are lymphoidcells. In another embodiment the method for inhibiting IL-31-inducedproliferation or differentiation of hematopoietic cells andhematopoietic cell progenitors is as disclosed above, wherein thelymphoid cells are macrophages or T cells.

Within another aspect, the present invention provides a method ofreducing IL-31-induced induced inflammation comprising administering toa mammal with inflammation an amount of a composition of a an antibodyas disclosed herein sufficient to reduce inflammation.

Within another aspect, the present invention provides a method ofsuppressing an inflammatory response in a mammal with inflammationcomprising: (1) determining a level of an inflammatory molecule; (2)administering a composition comprising an antibody as disclosed hereinin an acceptable pharmaceutical vehicle; (3) determining a postadministration level of the inflammatory molecule; (4) comparing thelevel of the inflammatory molecule in step (1) to the level of theinflammatory molecule in step (3), wherein a lack of increase or adecrease the inflammatory molecule level is indicative of suppressing aninflammatory response. In one embodiment, the antibody is as disclosedabove, wherein the antibody further comprises a radionuclide, enzyme,substrate, cofactor, fluorescent marker, chemiluminescent marker,peptide tag, magnetic particle, drug, or toxin.

Within another aspect, the present invention provides a method forinhibiting IL-31-induced proliferation or differentiation ofhematopoietic cells and hematopoietic cell progenitors comprisingculturing bone marrow or peripheral blood cells with a compositioncomprising an amount of an antibody as disclosed herein sufficient toreduce proliferation or differentiation of the hematopoietic cells inthe bone marrow or peripheral blood cells as compared to bone marrow orperipheral blood cells cultured in the absence of soluble cytokinereceptor. In one embodiment the method for inhibiting IL-31-inducedproliferation or differentiation of hematopoietic cells andhematopoietic cell progenitors is as disclosed above, wherein thehematopoietic cells and hematopoietic progenitor cells are lymphoidcells. In another embodiment the method for inhibiting IL-31-inducedproliferation or differentiation of hematopoietic cells andhematopoietic cell progenitors is as disclosed above, wherein thelymphoid cells are macrophages or T cells.

Within another aspect, the present invention provides a method ofreducing IL-31-induced induced inflammation comprising administering toa mammal with inflammation an amount of a composition of a an antibodyas disclosed herein sufficient to reduce inflammation.

Within another aspect, the present invention provides a method ofsuppressing an inflammatory response in a mammal with inflammationcomprising: (1) determining a level of an inflammatory molecule; (2)administering a composition comprising an antibody as disclosed hereinin an acceptable pharmaceutical vehicle; (3) determining a postadministration level of the inflammatory molecule; (4) comparing thelevel of the inflammatory molecule in step (1) to the level of theinflammatory molecule in step (3), wherein a lack of increase or adecrease in the inflammatory molecule level is indicative of suppressingan inflammatory response.

Within another aspect, the present invention provides a method oftreating a mammal afflicted with an inflammatory disease in which IL-31plays a role, comprising: administering an antagonist of IL-31 to themammal such that the inflammation is reduced, wherein the antagonist isselected from the group consisting of an antibody or binding polypeptidethat specifically binds a polypeptide or polypeptide fragment of IL-31(SEQ ID NO:2). In one embodiment, the method of treating a mammalafflicted with an inflammatory disease is as disclosed above, whereinthe disease is a chronic inflammatory disease. In another embodiment,the method of treating a mammal afflicted with an inflammatory diseaseis as disclosed above, wherein the disease is a chronic inflammatorydisease selected from the group consisting of: inflammatory boweldisease; ulcerative colitis; Crohn's disease; atopic dermatitis; eczema;and psoriasis. In another embodiment, the method of treating a mammalafflicted with an inflammatory disease is as disclosed above, whereinthe disease is an acute inflammatory disease. In another embodiment, themethod of treating a mammal afflicted with an inflammatory disease is asdisclosed above, wherein the disease is an acute inflammatory diseaseselected from the group consisting of: endotoxemia; septicemia; toxicshock syndrome; and infectious disease. In another embodiment, themethod of treating a mammal afflicted with an inflammatory disease is asdisclosed above, wherein the antibody further comprises a radionuclide,enzyme, substrate, cofactor, fluorescent marker, chemiluminescentmarker, peptide tag, magnetic particle, drug, or toxin.

Within another aspect, the present invention provides a method fordetecting inflammation in a patient, comprising: obtaining a tissue orbiological sample from a patient; incubating the tissue or biologicalsample with an antibody as disclosed herein under conditions wherein theantibody binds to its complementary polypeptide in the tissue orbiological sample; visualizing the antibody bound in the tissue orbiological sample; and comparing levels of antibody bound in the tissueor biological sample from the patient to a normal control tissue orbiological sample, wherein an increase in the level of antibody bound tothe patient tissue or biological sample relative to the normal controltissue or biological sample is indicative of inflammation in thepatient.

Within another aspect, the present invention provides a method fordetecting inflammation in a patient, comprising: obtaining a tissue orbiological sample from a patient; labeling a polynucleotide comprisingat least 14 contiguous nucleotides of SEQ ID NO:1 or the complement ofSEQ ID NO:1; incubating the tissue or biological sample with underconditions wherein the polynucleotide will hybridize to complementarypolynucleotide sequence; visualizing the labeled polynucleotide in thetissue or biological sample; and comparing the level of labeledpolynucleotide hybridization in the tissue or biological sample from thepatient to a normal control tissue or biological sample, wherein anincrease in the labeled polynucleotide hybridization to the patienttissue or biological sample relative to the normal control tissue orbiological sample is indicative of inflammation in the patient.

The invention is further illustrated by the following non-limitingexamples.

EXAMPLES Example 1 Generation of Rat Anti-Mouse IL-31 MAbs

A. Immunization and Serum Screening of Rats

Four 3 month old female Sprague-Dawley rats (Charles River Laboratories,Wilmington, Mass.) were immunized with mouse IL-31. The rats wereinitially immunized by intraperitoneal injection with ˜290 ug ofpurified, recombinant mouse IL-31 (produced in BHK cells) fused at theC-terminus with a peptide consisting of the sequence EYMPME (SEQ ID NO:7) (hereafter referred to as mIL31-CEE) in combination with CompleteFreund's Adjuvant (Pierce, Rockford, Ill.) as per manufacturer'sinstructions. Following the initial immunization each of the ratsreceived an additional 150 ug of mIL-31-CEE in Incomplete Freund'sAdjuvant via the intraperitoneal route every two weeks over a six weekperiod. Seven days after the third and fourth immunizations the ratswere bled via the retroorbital plexus and the serum separated from theblood for analysis of its ability to bind to mIL-31-CEE in solution andto inhibit (as measured by neutralization) the stimulatory activity ofmIL-31-CEE on a cell line transfected with the mouse IL-31RA.

The ability of the rat anti-mouse IL-31 antibodies in the antisera tobind to mIL-31-CEE was assessed using a “capture” style ELISA assay. Inthis assay, wells of 96 well polystyrene ELISA plates were first coatedwith 100 uL/well of goat anti-rat IgG, Fc specific antibody (JacksonImmunoresearch) at a concentration of 500 ng/mL in 0.1M Na2CO3, pH 9.6.Plates were incubated overnight at 4° C. after which unbound antibodywas aspirated and the plates washed twice with 300 uL/well of PBS-Tween(0.137M NaCl, 0.0027M KCl, 0.0072M Na2HPO4, 0.0015M KH2PO4, 0.05% v/vpolysorbate 20, pH 7.2). Wells were blocked with 200 uL/well ofSuperBlock (Pierce, Rockford, Ill.) for 5 minutes at room temperature(RT), the SuperBlock flicked off the plate and the block repeated oncemore after which the plates were washed twice with PBS-Tween. Serial10-fold dilutions (in PBS-Tween plus 1% w/v bovine serum albumin (BSA)and 0.05% v/v Proclin 300, pH 7.2=dilution buffer) of the sera wereprepared beginning with an initial dilution of 1:1000 and ranged to1:1,000,000. Triplicate samples of each dilution were then transferredto the assay plate, 100 uL/well, in order to bind rat IgG in the sera tothe assay plate through the Fc portion of the molecule. Normal rat seraserved as a negative control. Following a 1 hour incubation at RT, thewells were aspirated and the plates washed twice as described above.Biotinylated mIL-31-CEE (12:1 molar ratio of biotin:protein) at aconcentration of 500 ng/mL was then added to the wells, 100 uL/well.Following a 1 hour incubation at RT, unbound biotinylated mIL-31-CEE wasaspirated from the wells and the plates washed twice. Horseradishperoxidase labeled streptavidin (Pierce, Rockford, Ill.) at aconcentration of 500 ng/mL was then added to each well, 100 uL/well, andthe plates incubated at RT for 1 hour. After removal of unbound HRP-SA,the plates were washed 5 times, 100 uL/well of tetramethyl benzidine(TMB) (BioFX Laboratories, Owings Mills, Md.) added to each well and theplates incubated for 5 minutes at RT. Color development was stopped bythe addition of 100 uL/well of 450 nm TMB Stop Reagent (BioFXLaboratories, Owings Mills, Md.) and the absorbance values of the wellsread on a Molecular Devices Spectra MAX 340 instrument at 450 nm.

The ability of the rat anti-mouse IL-31 antibodies in the antisera toinhibit (as measured by neutralization) the stimulatory activity ofmouse IL-31 through its cognate receptor was assessed using a cell basedneutralization assay that employed a mIL-31RA/OSMRbeta transfected Baf3cell line with a luciferase reporter system(Baf3/KZ134/mcytor17/mOSMRbeta) and could be activated via stimulationof the cells by mouse IL-31. For this assay, an initial 1:250 dilutionin assay media (RPMI 1640, 10% FBS, 2 mM L-glutamine, 1 mM sodiumpyruvate, 1× penicillin-streptomycin-neomycin (Invitrogen, Carlsbad,Calif.)) of each antiserum was prepared and then each of these wasserial 2-fold diluted to a final dilution of 1:32000. To each dilutionof antisera was added an equal volume of mIL-31-CEE diluted to 4 ng/mLin assay buffer for a total of volume of 100 uL in the wells. Theantibody/cytokine mixtures were incubated at RT for 0.5 hour after whichthe target cells were washed from their growth media, adjusted to adensity of 300,000 cells/mL and added to the antibody/cytokine mixtures,100 uL/well. Assay media containing 2 ng/mL of mIL-31 and no antiseraserved as a negative control and indicated the maximal stimulation thatcould be achieved in the assay. Following incubation at 37° C., 5% CO2for 16-24 hours the plates were centrifuged at 1500 RPM for 5 minutes,the media carefully flicked off and 25 uL of 1× cell lysis buffer(Promega, Madison, Wis.) added to each well. The plates were gentlyshaken for 10 minutes at RT to allow for complete cell lysis and thencell lysates were transferred to solid white 96-well plates(Corning/Costar 3917, Acton, Mass.). 40 uL of luciferase assay substrate(Promega) was added to each well. Wells were then assessed forluciferase activity (representing IL-31 activation of the STAT reporterconstruct) on a luminometer using a 5 second integration interval.

Both the “capture” ELISA assay as well as the cell based neutralizationassay indicated that all four rats developed a significant antibodyresponse to mIL-31 although one rat clearly generated a strongerresponse than the others. In general, the response as measured by the“capture” ELISA closely paralleled that seen with the cell basedneutralization assay suggesting that IgG class antibody was primarilyresponsible for the inhibition of mIL-31.

B. Fusion

Four weeks after the last intraperitoneal immunization, the rat with themost significant mIL-31 neutralization titer was immunized a final timewith approximately 150 ug of mIL-31-CEE in PBS via intravascularinjection. Five days later, the spleen and lymph nodes of this rat wereharvested, prepared into a single cell suspension and fused to the Sp2/0mouse myeloma cell line (Shulman, M. et al., Nature 276:269-270, 1976)at a 4:1 lymphoid cell:myeloma cell ratio with PEG 1500 using standardmethods known in the art (Harlow, E. and Lane, D. 1988. “Antibodies ALaboratory Manual”, Cold Spring Harbor Laboratory, Cold Spring Harbor,N.Y.). The fusion mixture was distributed into a series of 96 wellflat-bottomed plates in combination with BALB/c thymocytes as a feederlayer (Oi, V. T. and Herzenberg, L. A. 1980. “Selected Methods inCellular Immunology”, B. B. Mishell and S. M. Shiigi, eds., pp. 351-372,Freeman, San Francisco). Wells of the fusion plates were fed once with a70% replacement of media and thymocytes after 4 days and again two dayslater with just media. Wells were assayed eight days after plating ofthe fusion.

C. Screening of the Fusion

The “capture” ELISA for mIL-31 as described above was used as theprimary screen except that hybridoma supernatants were tested undilutedand were replica plated onto the assay plates from the culture plates.Approximately 170 positive wells were identified. Supernatants from eachof these wells as well as a few negative wells were then assessed fortheir ability to inhibit mIL-31 in the cell based neutralization assaydescribed earlier. Each was tested at a 1:8 final dilution in assaymedia. At the latter dilution, non-specific stimulatory components inthe hybridoma supernatants were sufficiently reduced such that they wereof minimal contribution to the stimulation index observed. A majority ofthe supernatants appeared to neutralize mIL-31 to some degree withapproximately ten of them demonstrating essentially completeneutralization and the remainder showing a continuum of inhibition up toa point where approximately another ten appeared to possess very littleif any neutralization potential. Hybridoma cells in approximately 150 ofthe “capture” ELISA positive wells were successfully expanded intoculture in 24 well plates. When the density of the 24 well cultures wasapproximately 4-6×10⁵ cells/mL, the supernatant (approximately 1.5 mL)was individually collected and stored for each well and the cells fromeach well cryopreserved.

Each of the 24 well supernatants was reanalyzed in both the “capture”ELISA and cell-based IL-31 neutralization assays employed in the fusionscreen. In addition, these supernatants were also tested in a “capture”ELISA employing the human homolog of IL-31 also constructed with theEYMPME (SEQ ID NO: 7) tag fused to the C-terminal of the IL-31 moleculeand produced in BHK cells. Results indicated that following expansion, amajority of the master well supernatants had retained their ability torecognize mouse IL-31 in solution. Among these “capture” assay positivewells, the mIL-31 inhibitory activity ranged from complete to nearlycomplete for about 20 supernatants to essentially no inhibition for10-15 supernatants. No crossreactivity to human IL-31-CEE was observedin the capture assay indicating that none of the rat anti-mIL-31antibodies crossreacted with the human IL31 homolog or recognized theCEE tag fused to the C-terminal of the mIL-31-CEE molecule.

D. Selection and Cloning of Hybridomas Producing Neutralizing Anti-mIL31MAbs

Cells in seven of the top ten IL-31 neutralizing master wells (271.5.7,271.9.4, 271.26.6, 271.27.4, 271.33.1, 271.33.3 and 271.39.4) werecloned in order to isolate a cloned hybridoma producing the neutralizingmAb of interest. Cells were cloned in the presence of thymocytes in 96well microtiter cell culture plates using a standard low-densitydilution (less than 1 cell per well) approach and monoclonality wasassessed by microscopic examination of wells for a single foci of growthprior to assay. Six days post-plating, all wells on the plates werescreened by the “capture” ELISA for mIL-31 specific IgG. Supernatantfrom 6-10 wells that was both positive for specific mAb and originatedfrom wells with only a single colony of hybridoma growth was collectedfrom each cloning set and rescreened at various dilutions in the“capture” ELISA as well as the cell-based neutralization assay toidentify a “best” neutralizing mAb producing clone. Results of thesetests indicated that the appropriate neutralizing mAb producinghybridoma clones were obtained only in sets 271.9.4, 271.26.6, 271.33.1,271.33.3 and 271.39.4. A “best” clone in each of these sets was reclonedand the subclones screened as described to yield the final hybridomalines 271.9.4.2.6, 271.26.6.6.1, 271.33.1.2.2, 271.33.3.2.1 and271.39.4.6.5. The rat IgG isotype of the mAb produced by each of thesehybridomas was determined using an ELISA that employed biotinylatedmouse anti-rat IgG isotype specific mAbs. All five mAbs were found tobelong to the IgG1 subclass. Hybridoma 271.26.6.6.1 was deposited withthe American Type Tissue Collection (ATCC, Manassas, Va.) patentdepository as an original deposit under the Budapest Treaty and givenATCC Accession No. PTA-6874.

Each of the fully cloned anti-mouse IL-31 mAb producing hybridomas wasadapted to growth in hybridoma serum free medium (Hybridoma-SFM,Invitrogen). Supernatant from high cell density cultures grown inHybridoma-SFM was centrifuged to remove cells and cell debris, filteredthrough a 0.2 μm filter and the mAb purified by protein G chromatographyusing standard methods known in the art.

E. Ranking In Vitro Specific Neutralizing Activity of MAbs

To rank the in vitro specific neutralizing activity of each of the fiverat anti-mouse IL-31 mAbs, each of the purified mAbs was retested in thecell-based neutralization assay described earlier with the exceptionthat mIL-31 was first added to cells and this mixture then added to theantibodies. In addition to neutralizing activity against mIL-31-CEE, themAbs were also evaluated against another form of mouse IL-31, termedc108smIL-31, in which the cysteine residue at position 108 had beenconverted to a serine residue. The latter material was produced in E.coli without the C-EE peptide. Both forms of mIL-31 were employed at afinal concentration of 1 and 5 ng/mL. The mAbs were adjusted to aconcentration of 20 ug/mL in assay media and tested in duplicate asserial 10-fold dilutions ranging from 10 ug/mL to 0.00001 ug/mL finalconcentration in the assay mixture. IC50 values were determined usingSoftmax software (Molecular Devices). Results are shown in Table 1 andshow that mAbs 271.26.6.6.1, 271.33.1.2.2 and 271.39.4.6.5 were the mostpotent neutralizing mAbs and were of similar potency in this in vitrotest. Interestingly, mAb 271.33.3.2.1 was much less effective than theother mAbs against the c108smIL-31 version of mIL-31 supporting theconclusion from the epitope binning studies that this antibody in alllikelihood has a different epitope specificity than the other four mAbs.The fact that this mAb was also much less effective against thec108smIL-31 version of mIL-31 as compared to the mIL-31-CEE versionsuggests that the epitope recognized by 271.33.3.2.1 might partiallyinvolve a glycosylation site on the IL-31 molecule.

TABLE 1 In Vitro Cell-Based Neutralization Activity of Rat Anti-MouseIL-31 MAbs mIL-31 Conc. IC50 (ng/mL) for mAbs version (ng/mL)271.9.4.2.6 271.26.6.6.1 271.33.1.2.2 271.33.3.2.1 271.39.4.6.5mIL31-CEE 1 11 3 2 13 2 5 30 14 13 36 12 c108smIL31 1 96 11 7 1248 9 5190 43 33 2551 40

Example 2 Generation of Mouse Anti-Human IL-31 mAbs

A. Immunization and Serum Screening of Mice

Two groups of six to eight week old female BALB/c mice, five animalseach, were immunized with human IL-31. Mice in Group 1 were immunized byintraperitoneal injection of purified, recombinant human IL-31 fused atthe C-terminal with a peptide consisting of the sequence EYMPME (SEQ IDNO: 7) (hereafter referred to as IL-31-CEE) in combination with Ribiadjuvant as per manufacturer's instructions. This protein was producedin BHK cells. Mice in Group 2 were similarly immunized with a purified,recombinant, mutated form of human IL-31 in which the cysteine residueat position 108 had been converted to a serine residue (hereafterreferred to as c108sIL-31). This material was produced in E. coliwithout the C-EE peptide. All mice received 50 ug of protein every twoweeks for a 10 week period. Seven to ten days after the third and fourthimmunizations the mice were bled via the retroorbital plexus and theserum separated from the blood for analysis of its ability to inhibitthe binding and subsequent stimulatory activity of human IL-31 to a cellline transfected with the human IL-RA.

The ability of the individual antisera to inhibit human IL-31 wasassessed using a luciferase based neutralization assay employingIL-31-CEE or c108sIL-31 and BaF3/KZ134/IL-31RA/OSMRbeta cells (seeExamples 3 and 4) with the following modifications. Individual antiserawere titrated in duplicate, via serial 4-fold dilutions down a 96 well,flat bottomed, white polystyrene plate (Corning/Costar 3917) startingwith an initial 1:250 dilution of the antisera in assay buffer (RPMI1640, 10% FBS, 1 mM sodium pyruvate, 2 mM L-glutamine, 100 U/mLpenicillin G sodium, 100 ug/mL streptomycin sulfate). In an attempt tonormalize the somewhat stimulatory effect of mouse serum in this assay,all dilutions except the initial 1:250 dilution were carried out inassay buffer plus 0.2% normal BALB/c mouse serum. The volume of dilutedantisera in each well was 100 uL. Cells were washed 1.5 times in assaybuffer, adjusted to a concentration of 3×106/mL, combined with eitherIL-31-CEE (100 pg/mL) or c108sIL-31 (30 pg/mL) and the mixture thenadded to the plates, 100 uL/well. Total assay volume was 200 uL/wellconsisting of 30,000 cells, IL-31 at a final concentration of 50 pg/mL(IL-31-CEE) or 15 pg/mL (c108sIL-31) and antisera at a final dilution of1:500, 1:2000, 1:8000, 1:32000, 1:128000, 1:512000, 1:2048000 and1:8192000. Plates were incubated at 37° C., 5% CO2 for 16-24 hours afterwhich they were centrifuged at 1250 RPM for 5 minutes, the mediacarefully flicked off and 25 uL of 1× cell lysis buffer added to eachwell. The plates were gently shaken for 10 minutes to allow for celllysis after which 40 uL of luciferase assay substrate was added to eachwell. Wells were then assessed for luciferase activity (representingIL-31 activation of the STAT reporter construct) on a luminometer usinga 4 second integration interval.

In general the antisera from mice immunized with IL-31-CEE was found toeffectively inhibit the stimulatory activity of both IL-31-CEE andc108sIL-31 and vice versa, in this assay. For this reason, furtherneutralization assays were usually carried out with only IL-31-CEE.

Those mice with the strongest neutralizing titers were used for a seriesof three fusions aimed at generating hybridomas producing monoclonalantibodies that could very effectively neutralize the interaction ofIL-31 with its cognate receptor.

B. Fusions

Fusion 291

The first fusion employed lymphoid node cells from one mouse immunizedwith IL-31-CEE and one mouse immunized with c108sIL-31. Each of theseanimals was immunized for a sixth time with 15 ug of the respectiveimmunogen diluted in PBS and administered via intravascular injectionthree weeks after their last immunization. Three days later, the spleenand lymph nodes from these mice were harvested, combined, processed intoa single cell suspension (total of 4.69×10⁸ cells) and then fused to aclone of the mouse myeloma cell line P3-X63-Ag8.653 (Kearney, J. F. etal., J Immunol. 123:1548-50, 1979) (designated P3-X63-Ag8.653.3.12.11)at a 2.3:1 lymphoid cell:myeloma cell ratio with 3 mL PEG 1500 for 2minutes 55 seconds using standard methods known in the art (Lane, R. D.J Immunol Methods 81:223-8, 1985). The fusion mixture was distributedinto a series of 96 well flat-bottomed plates, fed once with a 70% mediareplacement after 4 days and assayed 6 days later.

Fusion 292

The second fusion employed lymphoid cells from one mouse immunized withIL-31-CEE. In addition to the five intraperitoneal immunizationsmentioned above, this mouse received an intravascular injection of 15 ugof IL-31-CEE in PBS three weeks after the last intraperitoneal injectionand a similar injection three weeks after the first intravascularimmunization. Three days later, the spleen and lymph nodes wereprocessed (total of 2.27×10⁸ cells) and fused to P3-X63-Ag8.653.3.12.11at a 2:1 lymphoid cell:myeloma cell ratio with 1.8 mL PEG 1500 for 2minutes 55 seconds as described above. The fusion mixture wasdistributed into a series of 96 well flat-bottomed plates, fed once witha 70% media replacement after 4 days and assayed 5 days later.

Fusion 294

The last fusion employed lymphoid cells from one mouse immunized withc108sIL-31 only. In addition to the five intraperitoneal immunizationswith this antigen described earlier, this mouse received anintravascular injection of 15 ug of c108sIL-31 in PBS six weeks afterthe last intraperitoneal injection and then again two weeks after thefirst intravascular injection. Three days later, the spleen and lymphnodes were processed (total of 1.586×108 cells) and fused toP3-X63-Ag8.653.3.12.11 at a 2:1 lymphoid cell:myeloma cell ratio with1.5 mL PEG 1500 for 2 minutes 55 seconds as described above. The fusionmixture was distributed into a series of 96 well flat-bottomed plates,fed twice with a 70% media replacement after 4 and 6 days and assayed 3days after the last feed.

C. Screening of Fusions

All three fusions were screened using the cell-based IL-31neutralization assay described above with two modifications. First,instead of diluted antisera in the assay plates, 100 uL of supernatantfrom each of the wells on the fusion plates was replica plated onto theassay plates. Second, the final concentration of IL-31-CEE in the assaymixture was 150 pg/mL.

In addition to the neutralization assay, several plates from eachfusion, chosen at random, were screened for IgG antibodies that couldbind to IL-31-CEE that had previously been adsorbed onto polystyreneELISA plates. The purpose of this assay was to identify master wellscontaining a hybridoma producing an anti-IL31 antibody that eitherpoorly neutralized IL-31 or completely failed to neutralize thiscytokine. In this assay, wells of 96 well polystyrene ELISA plates wereinitially coated with 50 uL/well of IL31-CEE at a concentration of 200ng/mL in 0.1M Na2CO3, pH 9.6. Plates were incubated overnight at 4° C.after which unbound antigen was aspirated and the plates washed twicewith 300 uL/well of PBS-Tween (0.137M NaCl, 0.0027M KCl, 0.0072MNa2HPO4, 0.0015M KH2PO4, 0.05% v/v polysorbate 20, pH 7.2). Wells wereblocked with 200 uL/well of PBS-Tween+1% BSA for 1 hour at roomtemperature (RT). Blocking solution was then flicked off the plates and50 uL of conditioned media from each well of the fusion plates replicaplated into the wells of the assay plate. Plates were incubated for 1hour at RT after which unbound antibody was aspirated and the plateswashed twice with 300 uL/well of PBS-Tween. HRP conjugated goatanti-mouse IgG, Fc specific antisera (Jackson Immunoresearch) wasdiluted 1:5000 in PBS-Tween+1% BSA and added to wells of the assayplates, 100 uL/well. Following a 1 hour incubation at RT, unbound secondstep antibody was aspirated from the wells and the plates washed 5times. 100 uL/well of tetramethyl benzidine (TMB) (BioFX Laboratories,Owings Mills, Md.) was then added to each well and the plates incubatedfor 5 minutes at RT. Color development was stopped by the addition of100 uL/well of 450 nm TMB Stop Reagent (BioFX Laboratories, OwingsMills, Md.) and the absorbance values of the wells read on a MolecularDevices Spectra MAX 340 instrument at 450 nm.

Results of the neutralization assays showed that 52 and 139 wells inFusion 291 and 292, respectively, contained an antibody that inhibitedat least 40% of the IL-31 stimulatory activity. A more stringentdefinition of positivity was applied to fusion 294 where it was observedthat 131 wells contained an antibody that inhibited at least 70% of theIL-31 activity. Results of ELISA assays to detect mAbs that bound toIL-31-CEE indicated that in a majority of cases, if a master well wasfound to contain an IgG antibody that bound to IL-31-CEE, it alsocontained an antibody that inhibited IL-31-CEE in the cell-basedneutralization assay. There were some wells, however, that were positivein the ELISA assay but which showed relatively weak inhibitory capacityin the cell-based neutralization assay and they were saved for lateranalysis as described below.

Hybridoma cells growing in the positive master wells were expanded intoculture in 24 well plates. When the density of the 24 well cultures wasapproximately 4-6×105 cells/mL, the supernatant (approximately 1.5 mL)was individually collected and stored for each well and the cells fromeach well cryopreserved.

D. Selection and Cloning of Master Wells to Isolate Hybridomas ProducingPotent IL-31 Neutralizing MAbs

Each of the new 24 well supernatants was reanalyzed for IL-31neutralization capacity using the cell-based IL-31 neutralization assayemployed in the fusion screen. Each supernatant was run undiluted and induplicate. Results indicated that following expansion, a majority of themaster well supernatants had retained inhibitory activity equal to orbetter than that observed in the original master screen. To betterdetermine which of the new master well supernatants possessed thestrongest inhibitory capacity, those supernatants that demonstratedapproximately 90% or better inhibition of IL-31-CEE in this assay werereanalyzed by testing dilutions of the supernatant in the cell-basedneutralization assay. Supernatants were titrated via serial 3-folddilutions into fusion media on the assay plates to yield 100 uL in eachwell of the following dilutions: neat, 1:3, 1:9, 1:27, 1:81 and 1:243and the assay carried out as described above for the fusion screen.While this assay clearly identified the most inhibitory supernatants, itwas unable to determine which ones had the highest specific activitybecause concentration of anti-IL31 antibody in the supernatants wasunknown.

To address the specific antibody concentration issue, each of thesupernatants was tested in titration format, using either serial 2-foldor 4-fold dilutions, on IL-31-CEE in the direct ELISA assay describedabove. After plotting the data in Microsoft EXCEL, the dilution ofsupernatant yielding half the maximal optical density (OD) observed inthe assay was determined which in turn provided some indication of therelative concentration of anti-IL-31 antibody in the supernatant.

By combining the data from the neutralization assay with that of theELISA assay, a relative specific activity was established for eachsupernatant and the twenty master wells containing the highestanti-IL-31 neutralization specific activity identified. Interestingly,all the most potent anti-IL-31 neutralizing master wells were derivedfrom fusion 292. It was noted in the neutralization data for thesemaster wells that while maximal IL-31 inhibition was achieved for eachsupernatant at the neat and 1:3 dilution, the absolute degree ofneutralization was slightly greater for some supernatants than others asreflected in slightly lower relative luciferase unit counts. This wasinterpreted as slightly different degrees of “complete” IL-31neutralization. By coupling this observation with the relativeneutralization specific activity for each master well, the list of thetwenty most potent neutralizing master wells was reduced to the apparentbest ten. These included 292.12, 292.39, 292.51, 292.63, 292.64, 292.72,292.84, 292.105, 292.109 and 292.118.

Cells in each of these top ten IL-31 neutralizing master wells werecloned in order to isolate a cloned hybridoma producing the neutralizingmAb of interest. Cells were cloned in 96 well microtiter cell cultureplates using a standard low-density dilution (less than 1 cell per well)approach and monoclonality was assessed by microscopic examination ofwells for a single foci of growth prior to assay. Cloning mediaconsisted of fusion media lacking the HAT component (IMDM, 10% FC1serum, 2 mM L-glutamine, 1× penicillin/streptomycin, 10% hybridomacloning factor (Roche Applied Science). Six to eight days post-plating,supernatants in all wells were screened by ELISA on plate boundIL-31-CEE. Cells from 4-6 wells in each set in which the supernatant wasstrongly positive for specific mAb and there appeared to be only asingle colony of hybridoma growth were expanded into 24 well culturesand resulting supernatants retested by ELISA on plate bound IL-31-CEEand by the cell-based IL-31 neutralization assay. Based on these resultsthe apparent most potent neutralizing clone in each set was recloned andscreened by ELISA as described above. If 95% or more of the growthpositive wells were also positive for specific mAb, further subcloningefforts were deemed unnecessary and the hybridomas declared clonal. Foronly one master well, 292.64, was a second round of subcloning necessaryto achieve the desired percentage of specific mAb positivity among theresulting clones. Cells from 5-6 wells in each final subclone set inwhich the supernatant was strongly positive for specific mAb and thereappeared to be only a single colony of hybridoma growth were expandedinto 24 well cultures. Each of the hybridoma clones was then adapted togrowth in media lacking hybridoma cloning factor (IMDM, 10% FC1 serum, 2mM L-glutamine, 1× penicillin/streptomycin) by splitting cells into thelatter media when cell density was appropriate. Following adaptation,supernatant was collected from the subclones in each set and screened byELISA on plate bound IL-31-CEE. Based on titer with respect to celldensity at the time of supernatant collection, a “best” final clone waschosen leading to the selection of the following group of final clones:292.12.3.1; 292.39.5.3; 292.51.5.2; 292.63.5.3; 292.64.6.5.5;292.72.3.1; 292.84.1.6; 292.105.4.1; 292.109.4.4; and 292.118.6.4.

The mouse IgG isotype of the mAb produced by each of these hybridomaswas determined using the Mouse Monoclonal Antibody IsoStrip test (RocheApplied Science). All of the mAbs were found to belong to the IgG1subclass except for 292.72.3.1 and 292.84.1.6 which were shown to belongto the IgG2a subclass.

E. Ranking In Vitro Specific Neutralizing Activity of Potent IL-31Neutralizing MAbs

To rank the in vitro specific neutralizing activity of the ten potentmouse anti-human IL-31 mAbs, exhausted supernatant from each of thefirst round clones was retested in the cell-based neutralization assaydescribed earlier. First, the amount of IgG in each supernatant wasdetermined by HPLC analysis on a protein G column using a mAb of knownconcentration as a standard. Each supernatant was then diluted to an IgGconcentration of 1 ug/mL in the same media used to generate theexhausted supernatant. The diluted supernatants were then titrated via10-fold serial dilution in media to yield a concentration range of 1ug/mL to 0.0001 ug/mL and tested in triplicate in the previouslydescribed cell-based neutralization assay with the final concentrationof IL-31-CEE set at 300 pg/mL (18.27 pM). Results of the assay are shownin Table 2 with the mAbs listed in order from most potent to leastpotent. MAbs 292.84.1 and 292.12.3 were the most potent neutralizersfollowed in turn by mAbs 292.72.3 and 292.63.5 which appeared to beapproximately half as potent as the former two. The remainder of themAbs were shown to be approximately 6-9 times less potent than the twobest mAbs.

TABLE 2 Ranking of the Potent Anti-IL31 Neutralizing MAbs by in vitroSpecific Neutralization Activity MAb IC₅₀ (ng/mL) IC₅₀ (pM)* 292.84.11.077 ± 0.021  7.18 ± 0.14 292.12.3 1.197 ± 0.044  7.98 ± 0.29 292.72.31.997 ± 0.027 13.31 ± 0.18 292.63.5 2.819 ± 0.034 18.79 ± 0.23 292.51.56.478 ± 0.130 43.19 ± 0.87 292.118.6 6.550 ± 0.154 43.67 ± 1.03292.109.4 8.286 ± 0.151 55.24 ± 1.01 292.39.5 8.633 ± 0.481 57.55 ± 3.20292.105.4 9.144 ± 0.281 60.96 ± 1.87 292.64.6 10.05 ± 0.295 67.00 ± 1.97*using a molecular weight of antibody = 150,000 daltons

Based on the above results, hybridomas 292.84.1.6, 292.12.3.1,292.72.3.1, 292.63.5.3 and 292.118.6.4 were chosen as representative ofthe different levels of specific neutralization capacity to be depositedwith the American Type Tissue Collection (ATCC, located at 10801University Blvd., Manassas, Va. 20110-2209 USA) patent depository as anoriginal deposit under the Budapest Treaty and were given the followingATCC Accession No.s.: clone 292.12.3.1 (ATCC Patent Deposit DesignationPTA-6815; deposited on Jun. 29, 2005); clone 292.72.3.1 (ATCC PatentDeposit Designation PTA-6816; deposited on Jun. 29, 2005); clone292.63.5.3 (ATCC Patent Deposit Designation PTA-6829; deposited on Jul.6, 2005); clone 292.118.6.4 (ATCC Patent Deposit Designation PTA-6830;deposited on Jul. 6, 2005); and clone 292.84.1.6 (ATCC Patent DepositDesignation PTA-6871; deposited on Jul. 19, 2005).

F. Selection and Cloning of Master Wells to Isolate Hybridomas ProducingPoor IL-31 Neutralizing MAbs

Of interest in the generation of anti-human IL-31 mAbs was the isolationof pairs of mAbs that could be used in a sandwich assay format toquantify the amount of IL-31 in different fluids. Such pairs of mAbstypically have specificity for different epitopes on the target moleculeand preferably do not cross compete for binding to that molecule. Toisolate candidate pairs of such mAbs, a strategy was chosen to pair anexcellent IL-31 neutralizing mAb with one possessing little if anyneutralization potential, assuming that two such different functionalantibodies in all likelihood bound to non-overlapping (spatiallyseparated) epitopes.

As noted earlier for the fusion screens, several plates from each fusionwere screened by ELISA on plate bound IL-31-CEE to identify anti-IL-31antibody positive master well supernatants. Comparison of the ELISAresults to those of the cell-based neutralization assay indicated thepresence of master wells that contained antibody that bound well toIL-31-CEE but did not neutralize this molecule very well in thecell-based neutralization assay. As was done with the more potentneutralizing master wells, hybridoma cells growing in these master wellswere expanded into culture in 24 well plates. When the density of the 24well cultures was approximately 4-6×10⁵ cells/mL, the supernatant(approximately 1.5 mL) was individually collected and stored for eachwell and the cells from each well cryopreserved.

These new supernatants were tested using the cell-based neutralizationassay (serial 3-fold dilutions starting with neat supernatant andproceeding to a final 1:243 dilution) as well as a “capture” style ELISAassay similar to that used in the development of the rat anti-murineIL-31 mAbs with the following differences; 1) sheep anti-mouse IgG, Fcspecific antibody (Jackson Immunoresearch) (1 ug/mL) as plate coatingantibody, 2) plates blocked once with PBS-Tween+1% BSA for 1 hr, 3) asingle titration of each supernatant added to wells (serial 3-folddilutions starting with neat supernatant and proceeding to a final1:2187 dilution), and 4) addition of biotinylated IL-31-CEE (3:1 molarratio of biotin:protein), 200 ng/mL. This assay was felt to be morepertinent than the binding of antibody to plate bound IL-31-CEE as itassessed the ability of antibody to bind to IL-31-CEE in solution, aproperty essential to a good antibody for sandwich style ELISAs. It wasin fact observed that a number of the master wells supernatantscontaining antibody that bound well to plate bound IL-31-CEE poorlyrecognized this molecule in solution.

To chose which wells to clone appropriate antibody secreting hybridomasfrom, 10 wells were identified (291.78, 292.152, 292.154, 294.35,294.144, 294.146, 294.154, 294.155, 294.158 and 294.163) whosesupernatant poorly neutralized IL-31-CEE in the neutralization assay(less than 50% but preferably only 1-20%) and also bound relatively wellto IL-31-CEE in solution (as noted by an OD of greater than 2.0 at neatconcentration of supernatant). Cloning, screening of clones, andselection of a best first round clone was performed as described abovefor the potent neutralizing wells.

To reduce the number of hybridomas going into further subcloning, twonew assays were performed with exhausted supernatant from each of theselected first round clones. The first assessment was an attempt togroup the mAbs on the basis of epitope specificity (“binning”) using theBiacore 3000 surface plasmon resonance instrument. One of the goodneutralizing mAb supernatants (292.64.6) and the 10 poorer neutralizingfirst round clone supernatants were run against each other and resultedin the identification of four apparent “bins”. Bin 1 consisted of thegood neutralizing antibody only. Bin 2 was comprised of 292.152.4,292.154.4, 294 35.2, 294.146.5 and 294.154.5. Bin 3 included 291.78.4,294.155.6, 294.158.5 and 294.163.2. Bin 4 contained only 294.144.3. Thesecond assay involved a repeat of the “capture” style ELISA only thistime, because of higher specific antibody concentration in thesupernatants as compared to the original master 24 well culturesupernatants, a more complete titration curve was obtained and allowedfor the determination of an EC50 for antibody binding to IL-31-CEE.Results are shown in Table 3 (along with the binning results and the %inhibition of IL-31-CEE activity in the cell-based neutralization assay)and indicated that there was a wide range in EC50 values (and byinference, affinity of the mAbs for IL-31-CEE) for the various mAbs.

TABLE 3 Summary Data for First Round Clone Culture Supernatant from LessPotent IL-31 Neutralizing Hybridomas % Neutralization EC₅₀ (ng/mL) ofIL31 activity in Epitope Bin for capture cell-based assay MAb (Biacore)of IL31-CEE (undiluted supernate) 291.78.4 3 10 94 292.152.4 2 182 25292.154.4 2 57.7 76 294.35.2 2 22.2 82 294.144.3 4 13.4 75 294.146.5 210.2 94 294.154.5 2 15.8 88 294.155.6 3 172 53 294.158.5 3 119 31294.163.2 3 24.2 47 292.64.6 1 3.4 100

With emphasis on selection of hybridomas producing mAbs that were 1) inepitope bins different from that of a good neutralizing mAb (292.64.6)and 2) of highest affinity as indicated by a low EC50 in the capturestyle assay, only first round clones 294.35.2, 294.144.3, 294.154.5 and294.1632 were brought to final clone status as described above for themore potent neutralizing mAbs. This further subcloning effort yieldedselection of the following group of final clones: 294.35.2.6.3;294.144.3.5; 294.154.5.6; and 294.163.2.1.

The mouse IgG isotype of the mAb produced by each of these hybridomaswas determined using the Mouse Monoclonal Antibody ISOSTRIP™ test (RocheApplied Science). All four mAbs were found to belong to the IgG1subclass. Samples of each of the four hybridomas were deposited with theAmerican Type Tissue Collection (ATCC, located at 10801 UniversityBlvd., Manassas, Va. 20110-2209 USA) patent depository as an originaldeposit under the Budapest Treaty and were given the following ATCCAccession Nos.: clone 294.163.2.1 (ATCC Patent Deposit DesignationPTA-6831; deposited on Jul. 6, 2005); clone 294.35.2.6.3 (ATCC PatentDeposit Designation PTA-6872; deposited on Jul. 19, 2005); clone294.154.5.6 ATCC Patent Deposit Designation PTA-6875; deposited on Jul.19, 2005); and clone 294.144.3.5 (ATCC Patent Deposit DesignationPTA-6873; deposited on Jul. 19, 2005).

G. Cross-Reaction of Mouse Anti-Human IL-31 mAbs with Mouse IL-31

All first round clone supernatants from the ten potent neutralizing mAbsas well as the ten less potent neutralizing mAbs were tested for theirability to recognize mouse IL-31 by ELISA on plate bound mIL-31-CEE. Nocross-reactivity was seen with any of the mAbs indicating that the mAbsappeared to have specificity for human IL-31. Furthermore these resultsshowed that none of the antibodies recognized the CEE peptide tag commonto the C-terminal end of both the human and mouse IL-31 recombinantmolecules used in these studies, a determination that was not made onthe original master well supernatants.

Example 3 IL-31RA/OSMRbeta Receptor Luciferase Assay

The KZ134 plasmid was constructed with complementary oligonucleotidesthat contain STAT transcription factor binding elements from 4 genes,which includes a modified c-fos Sis inducible element (m67SIE, or hSIE)(Sadowski, H. et al., Science 261:1739-1744, 1993), the p21 SIE1 fromthe p21 WAF1 gene (Chin, Y. et al., Science 272:719-722, 1996), themammary gland response element of the β-casein gene (Schmitt-Ney, M. etal., Mol. Cell. Biol. 11:3745-3755, 1991), and a STAT inducible elementof the Fcg RI gene, (Seidel, H. et al., Proc. Natl. Acad. Sci.92:3041-3045, 1995). These oligonucleotides contain Asp718-XhoIcompatible ends and were ligated, using standard methods, into arecipient firefly luciferase reporter vector with a c-fos promoter(Poulsen, L. K. et al., J. Biol. Chem. 273:6229-6232, 1998) digestedwith the same enzymes and containing a neomycin selectable marker. TheKZ134 plasmid was used to stably transfect BaF3 cells, using standardtransfection and selection methods, to make the BaF3/KZ134 cell line.

A stable BaF3/KZ134 indicator cell line, expressing the full-lengthIL-31RA or IL-31RA/OSMRbeta receptor was constructed. Clones werediluted, plated and selected using standard techniques. Clones werescreened by luciferase assay (see B, below) using the human IL-31conditioned media or purified IL-31 protein as an inducer. Clones withthe highest luciferase response (via STAT luciferase) and the lowestbackground were selected. Stable transfectant cell lines were selected.The cell lines were called BaF3/KZ134/IL-31RA orBaF3/KZ134/IL-31RA/OSMRbeta depending on the receptors transfected intothe cell line.

Similarly, BHK cell lines were also constructed using the methoddescribed herein, and were used in luciferase assays described herein.The cell lines were called BHK/KZ134/IL-31RA orBHK/KZ134/IL-31RA/OSMRbeta depending on the receptors transfected intothe cell line.

BaF3/KZ134/IL-31RA and BaF3/KZ134/IL-31RA/OSMRbeta cells were spun downand washed in mIL-3 free media. The cells were spun and washed 3 timesto ensure removal of mIL-3. Cells were then counted in a hemacytometer.Cells were plated in a 96-well format at about 30,000 cells per well ina volume of 100 μl per well using the mIL-3 free media. The sameprocedure was used for untransfected BaF3/KZ134 cells for use as acontrol in the subsequent assay. BHK/KZ134/IL-31RA orBHK/KZ134/IL-31RA/OSMRbeta cells were plated in a 96-well format at15,000 cells per well in 100 μl media. Parental BHK/KZ134 cells wereused as a control.

STAT activation of the BaF3/KZ134/IL-31RA, BaF3/KZ134/IL-31RA/OSMRbeta,BHK/KZ134/IL-31RA, or BHK/KZ134/IL-31RA/OSMRbeta cells is assessed usingconditioned media or purified protein. One hundred microliters of thediluted conditioned media or protein is added to the BaF3/KZ134/IL-31RA,BaF3/KZ134/IL-31RA/OSMRbeta, BHK/KZ134/IL-31RA, orBHK/KZ134/IL-31RA/OSMRbeta cells. The assay using the conditioned mediais done in parallel on untransfected BaF3/KZ134 or BHK/KZ134 cells as acontrol. The total assay volume is 200 μl. The assay plates areincubated at 37° C., 5% CO₂ for 24 hours at which time the BaF3 cellsare pelleted by centrifugation at 2000 rpm for 10 min., and the media isaspirated and 25 μl of lysis buffer (Promega) is added. For the BHK celllines, the centrifugation step is not necessary as the cells areadherent. After 10 minutes at room temperature, the plates are measuredfor activation of the STAT reporter construct by reading them on aluminometer (Labsystems Luminoskan, model RS) which added 40 μl ofluciferase assay substrate (Promega) at a five second integration.

Example 4 Luciferase Assay on Human Transformed Epithelial Cell LinesVia Transient Infection with an Adenoviral STAT/SRE Reporter Gene

Inhibition, reduction, and/or neutralization of IL-31 activity can bemeasured by the luciferase assay. For example, human transformed celllines can be seeded in 96-well flat-bottom plates at 10,000 cell/well inregular growth media as specified for each cell type. The following day,the cells are infected with an adenovirus reporter construct, KZ136, ata multiplicity of infection of 5000. The KZ136 reporter contains theSTAT elements in addition to a serum response element. The total volumeis 100 ul/well using DMEM supplemented with 2 mM L-glutamine (GibcoBRL),1 mM Sodium Pyruvate (GibcoBRL) and 1× Insulin-Transferrin-Seleniumsupplement (GibcoBRL) (hereinafter referred to as serum-free media).Cells are cultured overnight.

The following day, the media is removed and replaced with 100 μl ofinduction media. The induction media is human IL-31 diluted inserum-free media at 100 ng/ml, 50 ng/ml, 25 ng/ml, 12.5 ng/ml, 6.25ng/ml, 3.125 ng/ml and 1.56 ng/ml. A positive control of 20% FBS is usedto validate the assay and to ensure the infection by adenovirus issuccessful. The cells are induced for 5 hours at which time the media isaspirated. The cells are then washed in 50 μl/well of PBS, andsubsequently lysed in 30 ml/well of 1× cell lysis buffer (Promega).After a 10-minute incubation at room temperature, 25 μl/well of lysateis transferred to opaque white 96-well plates. The plates are then readon the Luminometer using 5-second integration with 40 μl/well injectionof luciferase substrate (Promega).

Example 5 Inhibition of Cytokine Production by IL-31 Antibodies

IL-31 has been shown to stimulate IL-6 production in DU145 (diseased andnormal cell lines); as well as stimulate a A549 cell lines (diseased andnormal) to stimulate IL-8 production, and to reduce IL-8 production inU2OS cell lines (diseased and normal). See published U.S. patentapplication (See publication number 20030224487, Sprecher, Cindy et al.,2003). As such the activity of the IL-31 monoclonal antibodies describedherein can be measured by an inhibition, reduction, and/orneutralization of IL-31 activity in these human disease-state epithelialcell lines.

A. Inhibition of Cytokine Production by Human Disease-State EpithelialCell Lines Cultured with Human IL-31

Cells are plated at a density of 4.5×10⁵ cells per well in a 6 wellplate (Costar) and cultured in respective growth media. The cells arecultured with test reagents; 100 ng/mL IL-31 (with and with out antibodychallenge), 10 ng/mL Interferon gamma (IFN gamma) (R&D Systems,Minneapolis, Minn.), 10 ng/mL Tumor Necrosis Factor alpha (TNF alpha)(R&D Systems, Minneapolis, Minn.), 10 ng/mL IL-1beta (R&D Systems,Minneapolis, Minn.) or 100 ug/mL Lipopolysaccharide (LPS) (Sigma).Supernatants are harvested at 24 and 48 hours and assayed for cytokines;GM-CSF (Granulocyte-Macrophage Colony-Stimulating Factor), IL-1b, IL-6,IL-8, MCP-1 (Macrophage Chemoattractant Protein-1) and TNFa. MultiplexAntibody Bead kits from BioSource International (Camarillo, Calif.) wereused to measure cytokines in samples. Assays are read on a Luminex-100instrument (Luminex, Austin, Tex.) and data is analyzed using MasterPlexsoftware (MiraiBio, Alameda, Calif.). Cytokine production (pg/mL) foreach cell line in the 24-hour samples is measured.

B. Inhibition of Cytokine Production by Normal Human Epithelial CellLines Cultured with Human IL-31

Cells are plated at a density of 1×10⁵ cells per well in a 24 well plateand cultured with test reagents; 1000 ng/mL, 100 ng/mL and 10 ng/mLIL-31 (with and with out antibody challenge), 10 ng/mL TNFa, 10 ng/mLOSM, 10 ng/mL IFNa, 10 ng/mL TGFb or 10 ng/mL Lymphotactin. Supernatantsare harvested at 24 and 48 hours and assayed for cytokines; IL-6, IL-8,MCP-1, RANTES and Eotaxin. Cytokines are assayed as previouslydescribed. Cytokine production (pg/mL) for each cell line in the 48-hoursamples is measured.

C. Inhibition of Cytokine Production by Human Disease-State EpithelialCell Lines Co-Cultured with Human IL_(—)31 and IFN Gamma

Cells are plated at a density of 2×10⁵ cells per well in 24 well plateand co-cultured with 10 ng/mL IFN gamma+/−IL-31 at 100 ng/mL, 10 ng/mLor 1 ng/mL. Supernatants were collected at 24 and 48 hours and assayed f(with and with out antibody challenge), or IL-8 and MCP-1. Cytokineproduction (pg/mL) for each cell line in the 24-hour samples ismeasured.

Example 6 Inhibition of IL-31 Effects on U937 Monocyte Adhesion toTransformed Bone Marrow Endothelial Cell (TRBMEC) Monolayer

It has been shown that IL-31 can synergiz can affect the basal adherenceof U937 cells to the endothelial monolayers. In particular, IL-31synergized with TNFalpha and further enhanced U937 adhesion. Seepublished U.S. patent application (See publication number 20030224487,Sprecher, Cindy et al., 2003. Thus inhibition of IL-31 by the anti-IL-31antibodies described herein can be measured with the following assay.

Transformed Bone Marrow Endothelial Cells (TRBMEC) are seeded in 96-welltissue clusters (Falcon) at a density of 25,000/well in medium M131(Cascade Biologics) supplemented with Microvascular Growth Supplement(MVGS) (Cascade Biologics). At confluence (24 hours later), cells areswitched to M199 (Gibco-Life Technologies) supplemented with 1% FetalBovine Serum (Hyclone). Human recombinant IL-31 (test reagent) is addedat various concentrations (from 0.4 to 10 ng/mL) with and withoutantibody challenge, to test for the effect of the protein on immunecell-endothelial cell interactions resulting in adhesion. Some wellsreceive 0.3 ng/ml Tumor Necrosis Factor (TNFalpha R&D Systems), a knownpro-inflammatory cytokine, in addition to IL-31, to test an effect ofthe protein on endothelial cells under inflammatory conditions. TNFalphaat 0.3 ng/ml alone is used as positive control and the concentrationused represents approximately 70% of the maximal TNFalpha effect in thissystem, i.e., it does not induce maximal adherence of U937 cells (ahuman monocyte-like cell line) to the endothelium. For this reason, thissetup can detect both upregulation and downregulation of the TNFalphaeffects. Basal levels of adhesion both with and without TNFalpha areused as baseline to assess effect of test reagents.

After overnight incubation of the endothelial cells with the testreagents, U937 cells, stained with 5 μM Calcein-AM fluorescent marker(Molecular Probes), the cells are suspended in RPMI 1640 (no phenol-red)supplemented with 1% FBS and plated at 100,000 cells/well on the rinsedTRBMEC monolayer. Fluorescence levels at excitation/emission wavelengthsof 485/538 nm (Molecular Devices micro-plate reader, CytoFluorapplication) are measured 30 minutes later, before and after rinsing thewell three times with warm RPMI 1640 (no phenol-red), to removenon-adherent U937. Pre-rinse (total) and post-rinse (adherence-specific)fluorescence levels are used to determine percent adherence (netadherent/net total×100=% adherence).

Example 7 IL-31 Bioassay Protocol

BAF3 cells transfected with hzCYTOR17 (IL-31RA), hOSMRB, and KZ134 aregrown to 5×10⁵ and 1×10⁶ cells/mL. Cells are washed with assay media(RPMI 1640, 10% FBS, L-Glutamine, Sodium Pyruvate, and Pen/Strep (allGibco)) and resuspended at 3×10⁵ cell/mL in assay medium. In a 96-wellopaque plate, hIL-31 standards are titered in duplicate from 600 pg/mLto 9.38 pg/mL in assay medium via a 100 μL/well, 1:2 serial dilution.Quality control standards are added in duplicate to the plate at 350pg/mL and 35 pg/mL in 100 μL. Test samples are often diluted 1:2 or 1:4and added in duplicate to the sample wells. 100 μL of the washed BAF3cells are added to each well for a final concentration of 3×10⁴cells/well. The plate is incubated for 16-24 hours at +37° C. in a 5%CO₂ incubator. The plate is centrifuged at 1200 RPM for 5 minutes, mediaflicked off and 25 μL/well of lysis buffer (Promega) added to each well.After 10 minutes the plate is read on a luminometer (Berthold). Theluminometer adds 40 μL/well of luciferase substrate mix (Promega) andintegrated the luminescence for a period of 4 seconds. Luminescencevalues are exported to a spreadsheet where they are analyzed andconverted into picograms of IL-31 per 10⁶ cells per mL of volume.

Example 8 IL-31 Involvement in Initiation and Perpetuation of ContactHyper-Sensitivity In Vivo

Method I

BALB/c mice are painted on shaved mid-back with 25 ul of 0.5% DNFBdissolved (2,4, dinitro-fluoro-benzene, Sigma, St. Louis Mo.) inacetone:olive oil (4:1) solution using a pipettor. A vehicle controlgroup receives 25 ul of acetone:olive oil only. After 5 days, mice areanaesthetized with isofluorane in an inhalation chamber and both earpinnae of experimental and control animals are measured with anengineer's micrometer (Mitutoyo) to obtain a baseline measurement. Miceare then challenged by applying 10 ul of 0.25% DNFB in acetone:olive oil(4:1) to both sides of each ear of all mice. Contact hyper-sensitivityis measured at 24 h and 48 h later as the difference between the rightear (challenged) and the left ear (unchallenged). All measurements aredone with an engineer's micrometer. Background values are determined bythe difference in ear swelling between the challenged and unchallengedears of naive mice.

Whole blood and serum for FACS and/or ELISA analysis are collected priorto sacrifice and ears are collected for histology.

Method II (Induces Th2 Responses)

BALB/c mice are painted on shaved mid-back with 100 ul of 0.5% FITC(fluorescein isothiocyanate) in a 1:1 solution of acetone/dibutylphthalate (MSDS available using pipettor on days 1, 2 and 8. On day 13,mice are anaesthetized with isofluorane in an inhalation chamber andboth ear pinnae of experimental and control animals are measured with anengineer's micrometer (Mitutoyo) to obtain a baseline measurement. Miceare challenged by applying 25 ul of 0.5% FITC (in 1:1 acetone/dibutylphthalate) to the dorsal surface of each ear. Contact hyper-sensitivityis measured at 24 h and 48 h later as the difference between the rightear (challenged) and the left ear (unchallenged). All measurements aredone with an engineer's micrometer. Background values are determined bythe difference in ear swelling between the challenged and unchallengedears of naive mice. Whole blood and serum for FACS and/or ELISA analysisare collected prior to sacrifice and ears are collected for histology.

Method III (Induces Th1 Responses)

BALB/c mice are painted on shaved mid-back with 25 ul of 2% oxazalone(in 4:1 acetone/olive oil) using pipettor. On day 7, mice areanaesthetized with isofluorane in an inhalation chamber and both earpinnae of experimental and control animals are measured with anengineer's micrometer (Mitutoyo) to obtain a baseline measurement. Miceare challenged by applying 8 ul of oxazalone to the dorsal surface ofeach ear. Contact hyper-sensitivity was measured at 24 h and 48 h lateras the difference between the right ear (challenged) and the left ear(unchallenged). All measurements are done with an engineer's micrometer.Background values are determined by the difference in ear swellingbetween the challenged and unchallenged ears of naive mice. Whole bloodand serum for FACS and/or ELISA analysis are collected prior tosacrifice and ears are collected for histology.

Involvement of IL-31 in the initiation and perpetuation of contacthyper-sensitivity is tested using the antibodies described hereinagainst IL-31 both at the sensitization and challenge phases of theexperiment.

Example 9 IL-31 Involvement in Atopic Dermatitis In Vivo

Methods I (Sensitization of NC/Nga Mice)

Male NC/Nga mice were purchased from CRL Japan. The mice were 4 weeksold on arrival and housed in SPF quarantine conditions for 4 weeks toacclimate. The mice were approximately 10-11 weeks old at the start ofthe antigen sensitization. Mice were anaesthetized with isofluorane andbacks were shaved with electric clippers. Approximately 10 ug ofDermatophagoides pteronyssinus (Dp) (Indoor Biotechnologies, specialorder) extract was injected intradermally at the nape of the neck 3times per week for 5 to 6 weeks until mice developed skin lesions.Control animals received 10 ul PBS intradermal injections 3 times perweek. The Dp extract was prepared according to method by Matsuoka andcolleagues. Matsuoka H., et al., Allergy: 58, 139 (2003). Briefly, 595mg Dp lyophilized spent culture extract was dissolved in 12 mL sterilePBS (Gibco). Dp was mixed in a 50 mL Falcon tube on a shaking rocker for30 minutes. The extract was spun for 10 minutes at 2000 rpm and thesupernatant was collected and aliquoted into 1 mL cryovial tubes andstored at −20° C.

Methods II (Sensitization of DO11.10 Mice)

DO11.10 transgenic mice were bred from an in-house colony and werebetween 9.5 and 14 weeks old at start of antigen sensitization. 24 hoursprior to epicutaneous sensitization mice were anaesthetized withisofluorane and the entire trunk (back and abdomen) of mice were shavedwith electric clippers. The mice were then tape stripped with Elastinsurgical tape (Johnson and Johnson) on the back. 1 cm2 sterile gauzepatches were wetted with either 500 ug ovalbumin (Calbiochem 32467) orsterile PBS (Gibco) and adhered to left backside of mice with DuoDermExtra Thin Dressing (ConvaTec 187932). The patch and dressing were thencovered in a body wrap of the Elastin surgical tape so mice could notremove or destroy the patches. Patches were worn for 7 days and removed.The mice were rested for two weeks before having another round ofepicutaneous sensitization. Mice received a total of three one-weeksensitizations.

Results

Immunohistochemical analysis of IL-31RA expression in lesional andnon-lesional skin from dust mite sensitized NC/Nga and OVA sensitizedDO11.10 animals showed that IL-31RA is expressed by epidermalkeratinocytes in mice, however no significant difference in levels ofexpression can be found between antigen sensitized versus PBS sensitizedanimals.

Example 10 Inhibition of Itch by Administration of Rat Anti-Mouse IL-31Antibodies

In another NC/Nga mouse study, male NC/Nga mice (SLC, Tokyo), age 4weeks were exposed to NC/Nga mice which were already exhibiting mild tomoderate dermatitis. At seven weeks the mice were divided into threegroups and received the following treatments. Every fifth day for sevenweeks the mice in one group were given IL-31 rat-anti-mouse injectionsat 10 mg/kg; one group were given injections of mouse serum albumin; andthe third group did not receive any treatment. The mice were assessedclinically twice a week for severity of skin lesions. Specifically,involvement of the skin (0=no involvement; 1=back involved; 2=back andface; 3=back, face, and ears) and severity of the lesions (0=normalskin; 1=scaly and dry; 2=nodular lesions; 3=bloody lesions). Inaddition, scratching was assessed. Mouse scratching using their hindtoes was automatically detected and objectively evaluated using MicroAct(Neuroscience, Tokyo, Japan). A small Teflon-coated magnet was implantedsubcutaneously into the dorsal side of both hind paws of the mice underKetalar/Xylazine anaesthesia. The mouse with magnets were placed in anobservation chamber surrounded by a round coil. The electric currentinduced in the coil by the movement of the magnets was amplified andrecorded. The analysis program used the following settings to registerscratch events: Threshold (V) 0.1; Event Gap (sec) 0.2; Max Freg (HZ)20.0; Min Freg (Hz) 2.0; and Min Duration (sec) 1.5. Note: in the NC/Ngamouse model, long lasting (>1.5 sec), but not short lasting scratchingbehavior (0.3-1.5 sec) are related to the dermatitis-specific itchsensation in mice. Overall primary endopoints measured were scratching,dermatitis, and body weight.

Results:

Taken over the entire period, treatment with the rat-anti-mouse IL-31antibody did not meet the primary end points. However, additionalanalysis revealed a significant reduction of scratch by the anti-IL-31antibody treatment in the time interval of days 22-43. In this timeperiod, as for the whole period, treatment with anti-Il-31 antibodiesdid not affect the development of atopic dermatitis-like lesions and didnot normalize the weight gain of diseased animals, perhaps due todelayed onset of clinical manifestations or by neutralizingauto-antibodies at termination of treatment. In this experiment,scratching behaviour, but not dermatitis, was already increased amongmost animals at the time when treatment with the antibody was initiated.

Example 11 IL-31 Involvement DTH In Vivo

Methods

To generate a DTH response, mice were sensitized to antigen on day 0 bysubcutaneous immunization at the base of the tail with 100 ug ovalbumin(OVA) in complete Freund's adjuvant (CFA, 50-100 ul total volume). Oneweek later mice were anesthetized with isofluorane in an inhalationchamber and both ear pinnae of experimental and control animals weremeasured with an engineer's micrometer (Mitutoyo) to obtain a baselinemeasurement. Mice were challenged intradermally with 10 ug OVA in PBS ina total volume of 10 ul into the left ear pinnae, just below the skinwithout hitting any veins. As a control, mice also received an injectionof 10 ul PBS in the right ear pinnae. In some cases, a separate controlgroup given an i.d. injection of OVA in the ear may also be treated withtopical corticosteroids as a positive control to inhibit the reaction.At 24 and 48 hr after challenge, mice were anesthetized and earthickness was measured. Results were expressed as: Specific earswelling=(24 hr measurement−0 hr measurement) for experimental ear−(24hr measurement−0 hr measurement) for negative control ear. Induration,the hallmark of DTH, is detectable by 18 hours after injection ofsensitized antigen and is maximal by 24-48 hours. The lag in the onsetof palpable induration is the reason for naming the response “delayedtype.”

Results

IL-31 transgenic mice were tested for DTH, however, due to an increasein ear thickness in un-challenged IL-31 transgenic animals, nostatistically significant difference in DTH could be determined betweenIL-31 Tg animals compared to wildtype controls. IL-31 receptor knockoutanimals were also tested in a DTH response and no significant differencein the DTH response could be observed between receptor knockout andwildtype animals.

Example 12 IL-31 Involvement in Induction of the Itch Response

Methods I (Capsaicin Treatment of IL-31 Treated Mice)

Ten week old BALB/c animals (CRL) were anaesthetized and injected with along-lasting analgesic agent, bupranorphine hydrochloride,subcutaneously at 0.1 mg/kg before injection of 0.25 ml of 4 mg/mlsolution of capsaicin in 10% ethanol+10% Tween-80 in salinesubcutaneously into scruff of neck. Animals were kept anaesthetized forat least 30 min following neurotoxin treatment. Forty-eight hours later,14-day osmotic pumps were implanted subcutaneously for continuousdelivery of 20 ug/day of IL-31 for 14 days. Mice were monitored dailyfor 6 days for alopecia and pruritis using the following criteria: 0=noscratching, animal appears normal, 1=thinning of coat in small areas,scratching noted, 2=minor hair loss (small patches), scratching,3=moderate hair loss, scratching, and 4=severe hair loss, excessivescratching.

Results demonstrated that while non-capsaicin-treated mice showed a meanscratch/hairloss score of 2.625 following three days of IL-31 delivery,capsaicin-treated mice showed a significantly lower score of 1. Thusmice treated with capsaicin prior to IL-31 delivery showed both a delayin incidence of scratching and hairloss and a lower score in theintensity of scratching and hairloss over the six days of theexperiment. These data suggest that IL-31 does induce some neuronalcomponent that contributes to the alopecia and pruritis induced byIL-31. Therefore, neutralization of IL-31 may decrease the incidence andintensity of itch, and therefore dermatitis, in patients suffering fromskin disorders that involve itch.

Methods II

Mice that are homozygous null for the Tac1 gene express no detectablesubstance P or neurokinin A. These mice have significantly reducednociceptive pain responses to moderate to intense stimuli and aretherefore a useful tool for studying the contribution of tachykininpeptides to pain/itch processing and inflammatory disease states. Twelveweek old, Tac1 knockout mice were implanted with 14-day osmotic pumpsdelivering 1 ug/day of IL-31 protein and observed daily for alopecia andpruritis using the following criteria: 0=no scratching, animal appearsnormal, 1=thinning of coat in small areas, scratching noted, 2=minorhair loss (small patches), scratching, 3=moderate hair loss, scratching,and 4=severe hair loss, excessive scratching.

Results of this study show that Tac1 deficient mice were lesssusceptible to IL-31 induced scratching/hairloss compared to wildtypecontrol mice. While 100% (10/10) of wildtype mice had developed evidenceof scratching and hairloss by day 6 of IL-31 treatment, only 33.3% (2/6)Tac1 deficient mice were showing signs of scratching and hairloss at thesame time-point. These data show that IL-31 induces a neuronal componentthat contributes to the scratch/hairloss phenotype in IL-31-treated miceand neutralization of IL-31 may decrease the incidence and intensity ofscratching in the context of dermatitis.

Methods III (Administration of IL-31 Neutralizing Antibody)

Normal female BALB/c mice (CRL) approximately 8 to 12 weeks old wereimplanted subcutaneously with 14-day osmotic pumps (Alzet, #2002)delivering 1 ug/day mIL-31. Groups of mice received intraperitoneal(i.p.) injections of rat anti-mouse IL-31 monoclonal antibody 10 mg/kg(200 ug/mouse) twice weekly starting 1 week prior to IL-31 delivery.Control groups of mice received i.p. injections of vehicle (PBS/0.1%BSA) with the identical dosing schedules. Mice were scored daily foralopecia and pruritis using the following criteria: 0=no scratching,animal appears normal, 1=thinning of coat in small areas, scratchingnoted, 2=minor hair loss (small patches), scratching, 3=moderate hairloss, scratching, and 4=severe hair loss, excessive scratching.

In all experiments, mice treated with rat anti-mIL-31 mAb had a delay inonset of symptoms of approximately 5 to 7 days and a lower overall scorefor alopecia and pruritis. All groups of mAb treated mice (regardless ofdose frequency or concentration) developed alopecia and pruritis similarto control mice by 13 day of the study. These data suggest thatneutralization of IL-31 can delay the onset of the scratch/hairlossresponse induced by IL-31.

Example 13 Characterization of Mouse-Anti-Human IL-31 MonoclonalAntibodies

A panel of 21 clonal hybridomas producing monoclonal antibodies (mAbs)specific for (recombinant) human interleukin 31 (IL31) were isolated.Ten hybridomas producing strongly neutralizing mAbs were isolated. Thesewere assigned to two sub-bins based on competitive binding studies.Eleven hybridomas producing weakly neutralizing mAbs were isolated.These were assigned to 4 additional bins based on competitive bindingstudies. One mAb worked well for Western Blotting, and it also workedwell for immunohistochemistry. Three mAbs suitable for use ascompetitive antagonists were identified. Monoclonal antibodies suitablefor use in sandwich immunoassays were also identified.

A. Epitope Binning by Biacore

Materials:

the capture antibody was Goat-anti-mouse IgG-Fc γ specific (Jackson#115-005-071); the blocking antibody was polyclonal IgG Fc fragment(Jackson Labs.); the antigen: rIL31 Produced in BHK with a CEE affinitytag; Biacore 1000; Biacore CM5 NHS-activated chip (Biacore, PNBR-1000-14).

Method:

Studies were performed on a Biacore1000™ system. BIAlogue v. 1.2 wasused for programming run methods. The goat-anti-mouse Fe antibody wascovalently immobilized to a Biacore CM5 chip via lysine residues to formthe active binding surface for the study. Each of the 21 mouseanti-huIL31 mAb clonal conditioned media supernatants was injected firstonto the goat-anti-mouse Fc surface, so that the primary mAb to betested could bind to the anti-mouse antibody surface in a favorableorientation. Remaining binding sites were then blocked with injection ofan irrelevant polyclonal IgG Fc fragment. The antigen (rIl31) was theninjected and captured to the primary antibody surface. This was followedby another injection of one of the 21 mouse anti-huIL31 mAb clonalconditioned media supernatants to test binding of the secondaryantibody. If the primary and secondary mAb competed for the same bindingsite on the antigen, the second mAb did not bind. If the two mAbs didnot compete for the same binding site on the antigen, the second mAb didbind.

Each supernatant was tested as the primary mAb in combination with theentire set of mAbs. Control cycles were performed to demonstrate lack ofresponse of the secondary mAb in the absence of primary mAb or antigen.Each mAb tested against itself was used as the negative control toestablished the level of background signal. Data was compiled usingBioEvaluation 3.2 RCI software, then loaded into Excel™ for dataprocessing. Between each cycle testing a monoclonal antibody pair, thegoat-anti-mouse Fc surface was regenerated with 2×30 sec washes of 50 mMHCl.

The strongly neutralizing mAbs (10) and weakly neutralizing mAbs (11)were studied in two separate panels, with the exception that when theweakly neutralizing mAbs were studied, mAb from hybridoma 292.64.6 wasincluded as a representative of the strongly neutralizing mAbs. Inaddition, after reviewing the relative affinity measurements andneutralization data in the context of the epitope bins for the first twobinning panels, a third panel of binning was performed on 8 “selected”mAbs including both strongly and weakly neutralizing mAbs.

Results:

Three panels testing monoclonal antibody pairings were completed foranalysis of both strongly neutralizing and weakly neutralizing mAbs. Thefirst panel tested all strongly neutralizing mAbs against one anotherand the second panel tested all of the weakly neutralizing mAbs (and arepresentative strongly neutralizing mAb from hybridoma 292.64.6)against each other. A third panel was completed to explicitly evaluatepairing of a subset of both strongly and weakly neutralizing mAbselected for further evaluation.

In addition to variations in the absolute response (RU) measured fordifferent mAb pairs, several of the mAb pairs behaved differently whenthe orientation of the pairs changed (i.e. one mAb of the pair used as aprimary vs secondary mAb). Such behavior is frequently observed and isgenerally attributed to the mAbs concerned having overlapping epitopes.

A total of four distinct bins were obtained from analysis of the firsttwo completed panels. For the first panel, all of strongly neutralizingantibodies grouped to together to define a single bin (bin 1: 292.12.3,292.39.5, 292.51.5, 292.63.5, 292.64.6, 292.72.3, 292.84.1, 292.105.4,292.109.4, 292.118.6). In the second panel, the weakly neutralizingantibodies were grouped into 3 additional major bins (bin 2: 294.35.2,294.146.5, 292.152.4, 292.152.4, 294.154.5; bin 3: 294.35.3, 291.78.4,294.158.5, 294.155.6, 294.163.2; bin 4: 294.144.3) that were distinctfrom a single representative of bin #1 (292.64.6). Additionally, many ofthe mAb pairings evaluated in panel 2 demonstrated a clear asymmetry ofresponse depending upon the orientation in which the mAbs were tested,indicating some overlap in binding sites. Two mAbs from bin 3, 294.35.3and 291.78.4, exhibited evidence of competition with mAbs in bin 2 whentested as the secondary mAb. Also in panel 2, the strongly neutralizingantibody 292.64.6 (bin 1) exhibited competition with mAbs in bin 3 whentested as the primary antibody.

After completion of the initial two binning panels, a group of the moststrongly neutralizing mAbs and the highest affinity weakly neutralizingmAbs were selected for further evaluation and were tested against eachother in panel 3. Results for the third panel were entirely consistentwith previous runs showing that the strongly neutralizing antibodiesbinned together and the weakly neutralizing antibodies separated intothe established multiple bins. In addition, the third panel demonstrateda partial overlap in binding of two mAbs from bin 2 (294.35.2 and292.154.4) with a subset of mAbs assigned to bin 1 (292.12.3, 292.72.3,292.84). This led to the assignment of sub-bins 1A and 1B within bin 1.In panel 3, mAbs from hybridoma 292.163.2 (bin 3) and 292.144.3 (bin 4)binned singly.

B. Microtiter-Plate (Label-Free Competitive ELISA) Epitope Binning

Materials:

The capture antibody was goat-anti-mouse IgG (Fc γ specific) Jackson#115-005-071; the blocking antibody was mouse IgG1, (ZymoGenetics);conditioned media supernatants from the hybridomas were used for thisstudy; the antigen was rIL31 Produced in BHK with a CEE affinity tagbiotinylated using the a Sulfo-NHS-Biotin kit (Pierce, Rockford, Ill.);Nunc Maxisorp 96-well plates (Nalge Nunc, Rochester, N.Y.); ELISA B(PBS, 0.1% Tween 20, 1% BSA); streptavidin-HRP (Pierce, Rockford, Ill.);TMB substrate (BioFX Laboratories, Owings Mills, Md.)

Method:

This method is similar to the label free competitive ELISA (LFC-ELISA)described by Nagata et al (2004). This method for epitope binningutilized biotinylated rIL31. Microtiter plates were coated at 100μL/well with 1 μg/mL of a goat anti-mouse IgG Fc-γ specific antibody(Jackson ImmunoResearch #115-005-071) diluted in ELISA B (PBS, 0.1%Tween 20, 1% BSA). After binding of this coating antibody for 3 hours atambient temperature, each mAb-containing conditioned media was dilutedin ELISA B to yield an approximate mAb concentration of 0.5 μg/mL andallowed to bind to the goat anti-mouse IgG coated plates overnight at 4°C. (mAb#1). In parallel, a second set of conditioned medias (mAb#2) werediluted in polystyrene test tubes to approximately 0.5 μg/mL mAb inELISA B, mixed with 50 ng/mL biotinylated rIL31 antigen, and incubatedovernight at 4° C. After incubation of mAb#1 with the coating antibody,the plates were blocked with an unrelated antibody to saturateunoccupied binding sites on the plate. The mAb#2-biotin-rIL31 mixtureswere added to the plate and allowed to bind. As a control for(non-competition) in the assay, 50 ng/mL biotinylated rIL31 was addeddirectly (without pre-incubation with mAb#2) to wells containingimmobilized mAb#1. After incubation with the biotinylated-IL31-mAb#2complex, streptavidin-HRP (Pierce, Rockford, Ill.) was added to theplate at 0.5 μg/mL. The plates were developed with TMB substrate (BioFXLaboratories, Owings Mills, Md.), and the absorbance of the individualwells at 450 nm was measured with a plate reader (Molecular DevicesSpectraMax340, Sunnyvale, Calif.). If mAb#1 recognized a differentepitope from mAb#2, the biotin-rIL31-mAb#2 complex bound to the plateresulting in a high absorbance reading. If mAb#1 recognized the sameepitope as mAb#2, the biotin-rIL31-MAb#2 complex did not bind to theplate resulting in a low absorbance reading.

Results:

The full panel of 21 mAbs were tested against themselves simultaneouslyin a series of six 96-well microtiter plates. Absorbance values at 450nm (A450 nm) were recorded for each combination and orientation andcompiled. In all cases, low absorbance values were obtained for theself-self combinations. In addition to the self-self control, a positivecontrol of 50 ng/mL rIL31-biotin (without competing mAb#2) was testedusing each primary mAb on every plate. Two positive control samples wereobtained for each primary mAb, and the values of the duplicate sampleswere similar. The absorbance values obtained from the positive controlwells (without mAb#2) for 9 of the 11 weakly neutralizing mAbs (frombins 2, 3, or 4) were less that the absorbance values measured for thecontrol samples for the remaining mAbs. Presumably this was due to thelower affinity (higher EC50) for those mAbs. To facilitate theinterpretation of the results, the absorbance values were normalized sothat the maximum absorbance measured for any combination of mAbs acrossa row (capture mAb (mAb#1) held constant) was assigned a value of 100%.The normalized values fell into two distinct groups: A large cluster ofvalues fell below a value of 32% consistent with competition, and asecond large cluster of values fell above 32% consistent with a lack ofcompetition. The 32% threshold value was used to assign each combinationand orientation of mAbs to one of two discrete categories(non-competition, and competition). Using the categorized data, binningwas performed automatically based on a hierarchical clusteringalgorithm. As was observed during the binning experiments using theBiacore, some pairs of mAbs categorized differently depending on whichmAb was used as the primary mAb. A high level of stringency, requiringcompetition in both orientations, was used to assign the mAbs to primarybins. Subsequently a less stringent criteria, requiring competition inone orientation only, was used to aid in the assignment of the mAbs tosub-bins based on minor differences in behavior. The normalized data wasgrouped according to the 5 primary bin assignments based on the highstringency criteria. Additionally, the combinations and orientations ofmAbs are color coded (white for competition and dark fornon-competition) to aid in visualizng the interactions that led to theassignment of mAbs to sub-bins.

The results of the binning by competitive ELISA are consistent with thebin assignments based on the results of the studies using the Biacore.Using the stringent binning criteria, the following bins were defined:

-   -   Bin #1 (containing all of the strongly neutralizing mAbs):        292.72.3, 292.64.6, 292.63.5, 292.51.5, 292.39.5, 292.12.3,        292.118.6, 292.109.4, 292.105.4, 292.84.1    -   Bin #2: 294.35.2, 294.154.5, 294.146.5, 292.154.4, 292.152.4    -   Bin #3: 294.35.3, 294.163.2, 294.158.5, 294.155.6    -   Bin #4: 294.144.3    -   Bin #5: 291.78.4

Focusing on bin #1, the mAbs from 3 of the hybridomas in bin #1(292.72.3, 292.12.3, 292.84.1) demonstrated competition with 3 of themAbs from bin #2 when used as the secondary mAb (mAb#2). Based on thisbehavior bin 1 was divided into two sub-bins; #1A and #1B, with bin #1Bcontaining the mAbs that compete with the bin 2 mAbs for binding. Bin#1A contains 292.64.6, 292.63.5, 292.51.5, 292.39.5, 292.118.6,292.109.4, 292.105.4. Bin #1B contains 292.72.3, 292.12.3, and 292.84.1.

Focusing on bin #2, three distinct interactions are apparent that wereused to divide bin #2 into 3 sub-bins. Bin #2A contains mAb fromhybridoma 294.146.5, which competes with all mAbs from both bins #1 and#2. Bin #2B contains mAbs from hybridomas 294.35.2 and 294.154.5, whichcompete with (secondary) mAbs from bin#1. Bin #2C contains mAbs fromhybridomas 292.154.4 and 292.152.4, which compete with the mAb from bin#4 when it is used as the secondary mAb.

Focusing on bins #3, #4, and #5: The mAbs in bin #3 (from hybridomas294.35.3, 294.163.2.1, and 294.155.6) compete with the mAbs from bothbins #4 and #5 when they are used as secondary mAbs. The mAbs in bins #4(from hybridoma 294.144.3.5) and #5 are mainly differentiated by theirinteraction with mAbs in sub-bin #2C (and the unique binding propertiesof the mAb from hybridoma 294.144.3 on Western blots).

When the full panel of 21 mAbs was tested simultaneously using theLFC-ELISA format, bin 1 and sub-bins #1A and #1B were clearlyidentified. Partial overlap of bins #2 and #3 was also identified whenthe complete panel of mAbs was tested simultaneously, and bin #2 wasdivided into 3 sub-bins One minor deviation from the bin assignmentsbased on Biacore data was the assignment of the mAbs from hybridomas291.78.4 and 294.144.3 to two distinct bins when strict criteria wereused with the LFC-ELISA data. Based on the Biacore studies, mAb fromhybridoma 291.78.4 had been assigned to bin #3.

C. Plate Based Affinity Measurement

Materials:

The capture polyclonal antibody was goat-anti-mouse IgG (Fc γ specific)(Jackson ImmunoResearch West Grove, Pa. #115-005-071); the blockingpolyclonal antibody was mouse anti-human IgG, (Jackson ImmunoResearch,#209-005-082); conditioned media supernatants from the hybridomas wereused for this study; the antigen was rIL31 Produced in BHK with a CEEaffinity tag biotinylated using the a Sulfo-NHS-Biotin kit (Pierce,Rockford, Ill.); Nunc Maxisorp 96-well plates (Nalge Nunc, Rochester,N.Y.); ELISA B (PBS, 0.1% Tween 20, 1% BSA); streptavidin-HRP (Pierce,Rockford, Ill.); TMB substrate (BioFX Laboratories, Owings Mills, Md.).

Method:

This method is similar to that described by van Heyningen (1986).Microtiter plates were coated at 100 μL/well with 1 μg/mL of a goatanti-mouse IgG Fc-γ specific antibody (Jackson ImmunoResearch#115-005-071) diluted in ELISA B (PBS, 0.1% Tween 20, 1% BSA). Afterbinding of this coating antibody for 3 hours at ambient temperature,each purified monoclonal antibody supernatant was diluted in ELISA B toyield and approximate mAb concentration of 1 μg/mL and allowed to bindto the plate for 1 hour at ambient temperature. A serial dilutions ofbiotinylated rIL31 antigen were prepared from 500 ng/mL to 0 ng/mL inELISA B and added to the wells. After incubation with the biotinylatedantigen, streptavidin-HRP (Pierce, Rockford, Ill.) at 0.5 μg/mL wasadded to the plate. The plates were developed with TMB substrate (BioFXLaboratories, Owings Mills, Md.), and the absorbance of the individualwells at 450 nm was measured with a plate reader (Molecular DevicesSpectraMax340, Sunnyvale, Calif.). Duplicate points were averaged andthe data was analyzed with a four-parameter fit. The “C” value of the 4parameter fit is reported as the apparent EC50 (ng/mL) and is thebiotin-rIL31 concentration that produces a half-maximal response in theassay.

Results:

Four-parameter fits were obtained from the experimental curves for all21 of the mAbs. The concentration of biotin-rIL31 producing half-maximalresponse (EC50) in the assay ranged from 3.3 to 236 ng/mL, with all 10of the strongly neutralizing mAbs exhibiting low and comparable EC50values (3.3-4.4 ng/mL).

D. Western Blotting

Materials:

The antigen was rIL31 Produced in BHK with a CEE affinity tag; 4-12%NuPAGE Bis-Tris gels (Invitrogen, Carlsbad, Calif.); Non-Reducing samplebuffer (Invitrogen, Carlsbad, Calif.); Molecular weight standards wereSeeBlue (Invitrogen); 1×MES running buffer (Invitrogen); Western Abuffer (50 mM Tris pH 7.4, 5 mM EDTA, 150 mM NaCl, 0.05% Igepal, 0.25%gelatin); 0.2 μm nitrocellulose membranes (Invitrogen); sheep anti-mouseIgG-HRP (Amersham, Piscataway, N.J.); Affinity purified rabbit pAbspecific for rIL31 (ZymoGenetics); donkey anti-rabbit Ig-HRP (Amersham);Lumi-Light Plus chemiluminescent Reagent (Roche, Mannheim, Germany);Lumi-Imager (Mannheim-Boehringer)

Method:

The ability of the mAbs to detect denatured and denatured/reduced rIL31on a Western blot was examined in this study. The rIL31 antigen wasmixed with either reducing or non-reducing sample buffer, heated at 70°C. for 10 min then loaded at 100 ng/lane on 4-12% NuPAGE Bis-Tris gels(Invitrogen, Carlsbad, Calif.). Molecular weight standards were SeeBlue(Invitrogen), and electrophoresis was performed in 1×MES running buffer(Invitrogen). Protein bands in the gels were transferred to 0.2 μmnitrocellulose membranes (Invitrogen) and blocked overnight in 2.5%non-fat dried milk in Western A buffer (50 mM Tris pH 7.4, 5 mM EDTA,150 mM NaCl, 0.05% Igepal, 0.25% gelatin). Nitrocellulose membranes wereprobed with each monoclonal antibody at an approximate concentration of0.1 μg/mL mAb. The blots were then probed with a secondary antibodyconjugated to horseradish peroxidase (sheep anti-mouse IgG-HRP;Amersham, Piscataway, N.J.). As a positive control, a separate Westernblot was probed with 0.1 μg/mL of a rabbit polyclonal antibody specificfor IL-31 (ZymoGenetics), and a secondary antibody conjugated tohorseradish peroxidase (donkey anti-rabbit Ig-HRP; Amersham). Bands onthe Western blots were detected with Lumi-Light Plus Reagent (Roche,Mannheim, Germany) and chemiluminescence recorded on a Lumi-Imager(Mannheim-Boehringer).

Results:

Western Blot analysis of the anti IL31 mAbs demonstrated that mAbs fromonly three of the 21 hybridomas detected the denatured rIL31 antigen.The strongest signal was obtained from the mAb produced by hybridoma294.144.3. This mAb also detected reduced/denatured rIL3I more stronglythat non-reduced/denatured rIL31. The intensity of signal observed withthis mAb was similar to that obtained with the polyclonal antibodycontrol. It is notable that the mAb from hybridoma 294.144.3 belongs toa bin separate from the other mAbs evaluated. Monoclonal antibodies fromtwo other hybridomas (292.84.1 and 292.64.6) detectednon-reduced/denatured rIL31 very weakly but did not detectreduced/denatured rIL31. This weak signal did not reproduce on thescanned blots. Both of these mAbs are neutralizing antibodies from bin#1.

Example 14 Relative Binding Affinity of the Rat Anti-Mouse MonoclonalAntibodies for the IL-31 Ligand

The relative binding affinity of four Rat-anti-Ms-IL-31-ligand MAb'sagainst IL-31 ligand was determined as follows. Clone 271.26.6.6.1,Clone 271.33.3.2.1, Clone 271.33.1.2.2, and Clone 271.39.4.6.5 wereassayed. Goat-anti-Rat IgG-Fc γ specific Antibody (Jackson) wasimmobilized onto a CM5 Biacore chip. After preliminary testing, theassay was further optimized to bind each MAb onto the anti-Rat capturesurface and then injected a concentration series of IL-31 ligand acrossthe MAb to see association and dissociation. After each run, the surfacewas regenerated back to the immobilized anti-Rat Antibody with 2injections of 30 mM HCl. Data was generated for each MAb and evaluationsoftware was used to define relative kinetic values.

The relative kinetic data generated by evaluation of the MAb-antigenbinding curves is shown in Table 4.

TABLE 4 Clone 271.26.6.6.1 271.33.3.2.1 271.33.1.2.2 271.39.4.6.5 ka(M−1s−1) 5.61E+05 1.43E+05 8.19E+05 8.94E+05 kd (s−1)  3.6E−04 5.46E−044.21E−04 6.21E−04 KD (M) 6.42E−10 3.81E−9  4.73E−10 6.94E−10 Chi2 0.1010.341 0.0917 1.92

Example 15 Reduction of TARC and MDC in Response to Anti-IL-31 Antibodyin AD Mouse Models

Method I

Six-week old male NC/Nga mice (CRL Japan) were sensitized intradermallywith 50 μg dust mite extract (D. pteronyssinus, Indoor Biotechnologies)three times a week on the back and scored for AD-like lesions. After 5weeks of sensitization the mice were euthanized and the right ears wereexcised and placed into a single well of a 48-well culture dish(Corning) supplemented with RPMI+2% FBS (GIBCO Invitrogen). Plates wereplaced in 5% CO2 humidity controlled incubators. Supernatants werecollected after 24 hours and frozen at −20° C. until further analysis.

Method II

Twelve-week old female NC/Nga mice (CRL Japan) were sensitizedintradermally with 10 μg SEB (Toxin Technology) in the ear and on theback three times per week. The mice were scored for AD-like lesions.After 5 weeks of sensitization the mice were euthanized and 6 mm biopsypunches were taken from the injected ear of each mouse and placed into asingle well of a 48-well culture dish supplemented with RPMI+2% FBS.Plates were placed in 5% CO2 humidity controlled incubators.Supernatants were collected after 24 hours and frozen at −20° C. untilfurther analysis.

Groups of mice in both studies were treated with either a rat anti-mouseIL-31 monoclonal antibody at 10 mg/kg or vehicle, intraperitoneally twotimes each week starting after 1 to 2 weeks of sensitization.

TARC and MDC concentrations in the 24-hour supernatant samples weremeasured by conventional ELISA (R&D Systems).

TARC and MDC concentrations were lower in ear supernatants fromanti-IL-31 treated mice compared to control mice in both studies,however, these results were not statistically significant when analyzedby ANOVA, probably due to small sample size. When the data from bothexperiments is combined and analyzed there is a statisticallysignificant difference between treated groups.

Example 16 Administration of IL-31 Neutralizing Antibody

Normal female BALB/c mice (CRL) approximately 8 to 12 weeks old wereimplanted subcutaneously with 14-day osmotic pumps (Alzet, #2002)delivering 1 ug/day mIL-31. Groups of mice received intraperitoneal(i.p.) injections of rat anti-mouse IL-31 monoclonal antibody 10 mg/kg(200 ug/mouse) twice weekly starting 1 week prior to IL-31 delivery.Control groups of mice received i.p. injections of vehicle (PBS/0.1%BSA) with the identical dosing schedules. Mice were scored daily foralopecia and pruritis using the following criteria: 0=no scratching,animal appears normal, 1=thinning of coat in small areas, scratchingnoted, 2=minor hair loss (small patches), scratching, 3=moderate hairloss, scratching, and 4=severe hair loss, excessive scratching.

In all experiments, mice treated with rat anti-mIL-31 mAb had a delay inonset of symptoms of approximately 5 to 7 days and a lower overall scorefor alopecia and pruritis. All groups of mAb treated mice (regardless ofdose frequency or concentration) developed alopecia and pruritis similarto control mice by 13 day of the study. These data suggest thatneutralization of IL-31 can delay the onset of the scratch/hairlossresponse induced by IL-31.

From the foregoing, it will be appreciated that, although specificembodiments of the invention have been described herein for purposes ofillustration, various modifications may be made without deviating fromthe spirit and scope of the invention. Accordingly, the invention is notlimited except as by the appended claims.

What is claimed is:
 1. An isolated polynucleotide encoding a monoclonalantibody or antigen-binding fragment thereof that specifically binds toa polypeptide consisting of amino acid residues 27-164 of SEQ ID NO:2,wherein the monoclonal antibody or antigen-binding fragment thereofbinds to the same epitope as the antibody produced by the hybridomahaving ATCC Patent Deposit Designation PTA-6815 for binding to thepolypeptide.
 2. The polynucleotide of claim 1, wherein the monoclonalantibody is the antibody produced by the hybridoma having ATCC PatentDeposit Designation PTA-6815.
 3. The polynucleotide of claim 2, whereinthe monoclonal antibody is humanized.
 4. The polynucleotide of claim 3,wherein the humanized monoclonal antibody comprises a humanimmunoglobulin constant region.
 5. The polynucleotide of claim 3,wherein the isotype of the humanized monoclonal antibody is IgG.
 6. Thepolynucleotide of claim 1, wherein the antigen-binding fragment is aFab, Fab′, F(ab′)₂, or single chain Fv.
 7. An isolated vector comprisingthe polynucleotide of claim
 1. 8. An isolated host cell comprising thevector of claim
 7. 9. A method of producing a monoclonal antibody orantigen-binding fragment thereof that specifically binds to apolypeptide consisting of amino acid residues 27-164 of SEQ ID NO:2comprising: a) culturing the host cell of claim 8 under conditionswherein the monoclonal antibody or antigen-binding fragment isexpressed; and b) recovering the monoclonal antibody or antigen-bindingfragment.